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	Trigonometrie		2009-08-07
		Michaël pose la question : Bonjour, Je cherche a vérifié cette relation de trigo, Tan^2x = Sin^2x +Sin^2x*Tan^2x. après de nombreux essais, j'arrive à ce résultat: Tan^2= 1-cos^2x + 1-cos^2x*(sin^2x/cos^2x) Merci de votre aide Claude Tardif lui répond.
	exercice de trigonométrie		2008-02-19
		Maxime pose la question : Montrer que dans un triangle quelconque le produit des cosinus des angles cosA*cosB*cosC est inférieur ou égal à 1/8. Pierre-Louis Gagnon et Thierry Moisan lui répond.
	cos^3x+sin^3x=1		2007-06-07
		sannier pose la question : bonjour je bloque sur l'equation: cos^3x+sin^3x=1 j'ai essayé toute les formules de trigonometrie je n'y arrive pas.connaissez vous un moyen de resoudre cette equation ou de m'orienter? Claude Tardif lui répond.
	problème de trigonométrie		2005-11-01
		Manon pose la question : Soit un triangle ABC, de cotes a , b et c, avec A=45° et B=60°. Apres avoir demontre que 3a²-2b²=0 (que jai fais en utilisant la regle du sinus) et a²-2c²+2ac=0 (que jai fait en utilisant la regle du cosinus), vous montrerez que laire du triangle ABC peut sexprimer: { [ 3 + racine carre 3 ] / 12 } b² unites. Je ne sais pas comment arriver a cette expression de laire. Je narrive pas a exprimer c² et ac en fonction de b².. et je pense que ca pourrait vraiment aider.. puisque je suis arrive a letape: ac[(racine carre 3) / 4] avec ac = a² + c² - b² et a² = 2/3 b² ms c²= 1/3 b² + ac Claude Tardif lui répond.
	Des tables trigonométriques		2003-11-20
		Jean-Jacques pose la question : Je suis à la retraite et en train de mettre à jour mes connaissances en trigonométrie. On peut facilement trouver les rapports entre les côtés d'un triangle droit ayant des angles secondaires de 30, 45 et 60 degrés, mais comment s'y prend-on pour calculer les rapports entre les côtés d'un triangle droit ayant des angles secondaires de valeurs intermdiaires. En d'autre mot, comment s'y prend-on pour faire le calcul détaillé des tables trigonométriques. J'ai cherché en vain dans divers textes de géométrie la réponse à cette question. Merci à l'avance pour l'attention que vous porterez à ma requête. Claude Tardif lui répond.
	Un peu de trigonométrie		2002-12-16
		Hubert pose la question : J'ai 37 ans et les mathématiques sont relativement loin dans ma mémoire, je voudrais savoir s'il existe un méthode pour résoudre une équation du type. a1*cos(x) + a2*sin(x) + a3*cos(2x) + a4*sin(2x) + a5 = 0 Claude Tardif lui répond.
	Question de trigonométrie		1997-12-11
		Jean-Pierre Quesnel pose la question : Je suis dans le désert et je parcours 1000 km à partir du point "A" jusqu'au point "B". Si je reviens au point "A" et fais une rotation de 8 degrés en faisant un autre 1000 km, quelle sera la distance en km entre les points "B" et "C". Diane Hanson et Penny Nom lui répond.
	sec(pi/12)		2022-03-23
		Diana pose la question : Please help me find the exact value of the following trigonometric expression: sec(pi/12). Thanks! Harley Weston lui répond.
	The height of a tree		2020-09-27
		Kerissa pose la question : A man height 1.2 m standing on top of a building 34.6m high views a tree some distance away he observes that the angle of depression of the base of the tree is 35 and the angle of depression of the top of the tree is 29, assuming that the tree stands of level ground. Determine the height of the tree. Penny Nom lui répond.
	A window problem		2020-08-18
		Richard pose la question : Hello, I was hoping your math specialists could help me with some formulas. I have shapes with specific known variables need to calculate others.   Example: We make a straight legged arch, This shape has a width a overall height and a leg height, The leg height is always less then the overall, And the top is arched. We have the width, Height, and leg size.   Need to calculate the length of the curve and sq ft of the shape. Harley Weston lui répond.
	x+sin(x)		2020-07-24
		adm pose la question : f(x)=x+sin(x) to evaluate f(30) use radians only or degrees Harley Weston lui répond.
	4sin(2x)cos(2x)+1=0		2020-07-02
		Sheila pose la question : 4sin(2x)cos(2x)+1=0 Penny Nom lui répond.
	An octagonal pool deck		2020-05-30
		lauchie pose la question : need help on cut sizes and cut degrees on octagon pool deck for a 24 foot round pool Harley Weston lui répond.
	A triangular garden		2020-05-24
		yoonji pose la question : the 3 sides of a triangular garden measure 200 ft., 250 ft., and 300 ft., respectively. the garden is to be divided by a line bisecting the longest side and drawn from the opposite vertex. what is the length of the bisecting line? Penny Nom lui répond.
	The side length of a hexagon		2020-02-05
		Rob pose la question : I have a hexagon that is 8 feet wide how long would the sides be? Penny Nom lui répond.
	The angle of a countersunk screw		2020-01-19
		Barbie pose la question : I need to be able to verify the angle used for the head of a countersunk screw. I have the diameter of the head, diameter of the shank and height between the two. I assume it would be considered a frustum. For example: A standard 90 degree metric flat head screw in an M2 diameter has a head diameter of 3.65mm, the actual thread diameter is 1.98mm and the height of the head is 1.20mm. How can I prove that it is a 90 degree angle? Harley Weston lui répond.
	cos (3pi/2 -x)		2019-11-20
		sam pose la question : 1. express the following as a trigonometric function of angle x for cos (3pi/2 -x) the answer in the textbook is -sin x but i am unsure of the process to get the answer. Penny Nom lui répond.
	A hexagonal planter		2019-11-19
		Colleen pose la question : I need to build a hexagon planter around a 32” square box. How long is each side of the hexagon? Penny Nom lui répond.
	A tube through a board at 45 degrees		2019-06-15
		Guy pose la question : I need to insert a tube 5/8" diameter into a board at a 45 degree angle. What size hole must I drill for the tube to fit snugly? Harley Weston lui répond.
	Subdividing land		2019-05-09
		Reuben pose la question : This is the measurements of my plot, A-B 46.7M, B-C 193.1, C-D 198.5 & D-A 208.25 (Clockwise naming of sides) angle A at 90 degrees. My questions is how do i subdivide this plot from the bottom having lines running parallel to C-D, eg two 2acre plots. the the remaining part becomes my compound (Uper part at line A-B) Harley Weston lui répond.
	cos(2x) = sin(x)		2018-12-18
		Liz pose la question : Determine all values of x in [0,2pi] that solve the equation Cos(2x)=sinx Penny Nom lui répond.
	Solve sinX=0.703X for X		2018-03-13
		PARAM pose la question : sinX=0.703X Penny Nom lui répond.
	0.366 x cos square (02 degree 17 mins 27 seconds)		2018-03-12
		michael pose la question : what is 0.366 x cos square (02 degree 17 mins 27 seconds) what is 0.366 x cos square (88 degree 26 mins 45 seconds) Penny Nom lui répond.
	Solve 2cos^2 x + sin x = 2		2017-10-25
		Yamama pose la question : hello ! I need help to solve this equation : 2cos^2 x + sin x = 2 Thank you very much Regards Penny Nom lui répond.
	Solve the equation completely cos 2x = 1		2017-06-08
		Lava pose la question : Solve the equation completely cos 2x = 1 Penny Nom lui répond.
	sin x/ 1+cos x = 1-cos x/ sin x		2017-04-16
		duiren pose la question : sin x/ 1+cos x = 1-cos x/ sin x Penny Nom lui répond.
	1/1-cosine(2x) - 1/1+ cos(2x)		2016-12-14
		Sean pose la question : 1/1-cosine(2x) - 1/1+ cos(2x) Penny Nom lui répond.
	Sin squared (x) + Sin (x) - 2		2016-06-25
		Sree pose la question : Reduce the below to a single term Sin squared (x) + Sin (x) - 2 Thanks Penny Nom lui répond.
	Trigonometry		2016-04-30
		Joel pose la question : I am bored with what I'm learning in 6th math class and want a challenge. I decided to look at trig. I couldn't find a good resource to teach me. Could someone either explain trig to me or show me a resource? Please don't say I'm too young to learn trig. I just am trying to learn. Penny Nom lui répond.
	sin 2x - sin x = 0		2016-04-24
		lilly pose la question : sin 2x - sin x = 0 0 Penny Nom lui répond.
	How can I express Sin 4A in term of Sin A?		2016-02-22
		Odukoya pose la question : How can I express Sin 4A in term of Sin A? Penny Nom lui répond.
	Shooting a ball at a target		2016-02-16
		Thys pose la question : Hi I have a problem with the formula that i use .(for programming) I have looked all over the web to find a solution but no luck. I have a cannon that shoots a ball at a target I use this formula to calculate what my initial velocity must be to hit the target at a angle of 30 degrees and a distance of 15m (the cannon and target position is known) It works perfectly if both is at same height but if one is higher or lower it miss. In an example I am working with the range is 30m, the angle is 45 degrees and the target is 10m higher than my position. Please help Formula = V0 = √RG / Sin(2α) Harley Weston lui répond.
	Find two values of x satisfying f(x)=1 where f(x)=sin(ln(x))		2016-01-21
		Ruth pose la question : I'm trying to find two values of x satisfying f(x)=1 where f(x)=sin(ln(x)) Penny Nom lui répond.
	Integration of dx/(x^2+1)^3		2016-01-07
		Ishank pose la question : Integration of dx/(x^2+1)^3 Penny Nom lui répond.
	Roof Square footage		2015-11-11
		Todd pose la question : Question from Todd: Good Day. I have to figure out the square footage of a quonset style roof that's not playing by the rules The building dimensions (rectangular) are 63'x135' the height of the roof is 9.25'. It not an entire Quonset, It's that style of roof,(curved). There are concrete block walls 10' up to the metal roof. Thank you! Todd Harley Weston lui répond.
	The domain of cos2x/(sinx-2)		2015-11-02
		Ameen pose la question : Find the domain of: f(x) = cos2x/(sinx-2) Penny Nom lui répond.
	A trig identity		2015-10-28
		Gail pose la question : verify sec(x) =cot(x)+tan(x)/csc(x), the csc(x) is under both the whole term cot(x) + tan(x) Penny Nom lui répond.
	sin(x/2)=cos(3x/2)		2015-09-27
		Valentine pose la question : sin(x/2)=cos(3x/2) I was trying to use cos3x=cos(2x+x) but there wasn't any progress Penny Nom lui répond.
	An angle of depression problem		2015-05-14
		haxir pose la question : find the height of the balloon directly above a town if the measure of angle of depression of another town 5km from the first town is 20°!6` Penny Nom lui répond.
	A limit		2015-03-13
		arthur pose la question : sin(x-1)/x^+x-2 Penny Nom lui répond.
	A fishfinder		2015-03-13
		Dave pose la question : I have a fishfinder that has a 20 degree cone on bottom of boat going to the bottom of the lake. How do I know the size of base diameter of the cone on the lake bottom depending on depth... such as 10 feet deep, for example? Penny Nom lui répond.
	The length of a ramp		2015-03-05
		Jaylynn pose la question : Hi, I've been trying to figure out how long my ramp would have to be in order to reach a height of 3.5 feet at a 30 degree angle for a sugar glider enclosure? Penny Nom lui répond.
	Bricks around a fire pit		2015-03-05
		Jayson pose la question : I have a round fire pit. It measures 25 inches in diameter. I have 12 inch long square bricks to go around it . My question is what degree do I cut the ends of these bricks to make them fit around this circle? The brick dimensions are 12"Lx6"Wx4"D. Harley Weston lui répond.
	Solve x=r(t-sin(t)) for t		2015-02-28
		David pose la question : I don't know how to write the function of t(x) by x=r(t-sin(t)). Can you teach me that? Harley Weston lui répond.
	Shadow angle		2015-01-29
		Lorilyn pose la question : A pole,110meters high,cast a shadow of 35meters long,what is the angle Penny Nom lui répond.
	The height of an obelisk		2015-01-27
		Fabian pose la question : Two observers on level ground position themselves 50 meters apart so that an obelisk is due north of position A and due west of position B. The angle of elevation to the top of the obelisk at position A and B is measured to be 29.9 degrees and 37.5 degrees respectively. Use this information to estimate the height of the obelisk. Penny Nom lui répond.
	sin x = cos x		2015-01-23
		Mubashir pose la question : there are two curves y=sinx and y=cosx intersecting at point where x is less than 90 and greater than 0.to find the point I made a equation sinx=cosx but donot know what to do further .please help me by solving this equation sinx=cosx also tell me that have you solved this equation by reference to the graph or by other means please do elaborate your solution in your answer. Penny Nom lui répond.
	1 + cot x divided by sin x + cos x		2015-01-15
		Torrie pose la question : I need to solve this problem in terms of Sin, but I'm having trouble. 1 + cot x divided by sin x + cos x Robert Dawson and Penny Nom lui répond.
	Two ships		2014-11-18
		Laura pose la question : 7. A ship leaves its home port and sails on a bearing of N28.17°E. Another ship leaves the same port at the same time and sails on a bearing of S61.83E. If the first ship sails at 24 mph and the second at 28 mph find the distance between the two ships after 4 hours. Robert Dawson lui répond.
	Trig functions and the unit circle		2014-10-02
		Jake pose la question : I was wondering what conclusions can be drawn about the trigonometric functions and how they work about the circle. Can you also please give me an explanation for it? Thank you. Penny Nom lui répond.
	Cutting a round cake so that it doesn't dry out		2014-08-26
		James pose la question : I'm wondering if there's a simple way to calculate the area between two parallel chords of a circle equidistant from its diameter, or if I have the area, to find the distance between the two chords. Here's my "problem". You may have heard of the way of cutting a round cake so that it doesn't dry out - make two parallel cuts (chords) the length of the cake, take the middle piece, then push the two pieces together. So I know the area of a 12" cake, and I want say, exactly an eighth of the cake. How wide do I cut the centre piece? Now to get even more difficult, the next day I want another eighth from the centre. How wide do I cut the next pieces, and so on...? Thanks, James Harley Weston lui répond.
	An arc subtended at the center of the Earth		2014-07-20
		Abhinav pose la question : Meerut is 60 km from Delhi. Find the nearest second the angle subtended at the center of the earth by the arc joining these two points,earth being regarded as a sphere of 5940 km radius. Penny Nom lui répond.
	Solve sin3x = cos2x		2014-07-14
		Emanuel pose la question : If sin3x=cos2x, find the value of x when x<0<90' Penny Nom lui répond.
	An antenna is atop a building		2014-07-05
		Andrew pose la question : If an antenna is atop a building 70 feet tall and the antenna has a beamwidth of 30 degrees how far from the building does the beam first touch the ground? Penny Nom lui répond.
	The height of a building		2014-05-17
		Jim pose la question : If I'm 150 ft. from the base of a building and the top of the building is approx. at a 75 degree angle, how do you calculate the height? Penny Nom lui répond.
	x - 2 Sin[x] = 0		2014-05-08
		chanmy pose la question : please help me to sole this equation x - 2 Sin[x] = 0,thank you Penny Nom lui répond.
	2cos^2x+cosx=sin^2x		2014-04-28
		MaryBeth pose la question : find all solutions of the following equation in the interval [0,pi] 2cos^x+cosx=sin^2x Robert Dawson lui répond.
	A triangular chicken pen		2014-04-27
		Cierra pose la question : Margaret has two lengths of fence, 20 meters and 24 meters, for two sides of a triangular chicken pen. The third side will be on the north side of the barn. One fence length makes a 75° angle with the barn. How many different pens can she build if one fence is attached at the corner of the barn? What are all the possible lengths for the barn side of the pen? Not sure what they are asking here... please show step by step what to do! Thank you so much! Penny Nom lui répond.
	Solve for theta		2014-04-25
		ALASTAIR pose la question : Hi, The question asks Solve for 'theta' cos2theta=sintheta x costheta. Substituting for cos2th either 1-2sin^2th or 2cos^2th does not give an equation in either sine or cosine alone how do I solve this please? Penny Nom lui répond.
	An octagonal pad		2014-04-25
		George pose la question : Hi, I need to pour a cement pad in the shape of an octagon that allows for 12" of clearance around the tank I will be putting on it. The tank has a radius of 16'. Penny Nom lui répond.
	A trig problem		2014-04-25
		srishti pose la question : Consider the points P= (-sin(a-b),-cosa), Q=(cos(a-b),sina), R=(cos(a-b+c),sin(a-c), where 0 Chris Fisher lui répond.
	The cosine of 2 theta		2014-04-10
		Kayla pose la question : Find \cos 2 \theta if \sin \theta = \frac{11}{61}. Robert Dawson lui répond.
	Cutting a hexagon from a disk		2014-04-05
		Paul pose la question : I am a machinist and sometimes need to make a hex from round material. If I know the distance of the flat sides opposite one another of my hex, how can I calculate the size of material I need to turn to give me the right diameter to finish the part with six sides? Penny Nom lui répond.
	A trig expression		2014-03-31
		Al pose la question : the question is Find the value of sq rt 1-cos40/ 1+cos40( that is the square root of the numerator and denominator) I can't see what the question is about or even less an obvious answer Can anybody help? Chris Fisher lui répond.
	The area of a 5 sided lot		2014-03-15
		Michael pose la question : Question from michael: This lot is in feet. 59x154x109x188x137 per the plot plan Harley Weston lui répond.
	The angle of depression		2014-03-08
		Ranger_minor pose la question : A woman of height 1.4 metres standing on the top of a building 34.6 metres high views a tree some distance away. she observes that the angle of depression of the bottom of the tree is 35 degrees and the angle of depression of the top of the tree is 29 degrees. assume that the building and the tree are on level ground : 1). calculate the distance of the woman from the top of the tree measured along her line of sight. Penny Nom lui répond.
	A limit with trig functions		2014-02-22
		pearl pose la question : (what is the value of limit of x as it approaches 0 of sin8x divided by cos6x) Penny Nom lui répond.
	A trig identity		2014-01-21
		Jhosseline pose la question : prove: sin (pi/2 - x) cot (x + pi/2)= -sinx Penny Nom lui répond.
	Radio direction finders		2014-01-09
		Nathan pose la question : Radio direction finders set up two points A and B, which are 2.5 miles apart on an east-west line. From A, it is found that the bearing of a signal from a radio transmitter is N36.33 degress E, while from B the bearing of the same signal is N53.67 degrees W. Find the distance of the transmitter from B. Penny Nom lui répond.
	conical lamp stand/staved wood		2013-12-07
		Henry pose la question : need to make lamp stand that is wooden staved; need it to be 25 inches at bottom and 10 inches at top; need to know angles for staves to be cut; the lamp stand will be rounded on a lathe and will be 40 inches tall John Lucas built one and it is pictured on his web page. thank you for any help/direction; I checked out the answered for cone shaped objects on your page but didn't find what I could use. thanks again. Henry--woodturner, parent teacher student . . . . . Harley Weston lui répond.
	2cos(2A)=-2^1/2		2013-11-14
		Mary pose la question : Solve the following trigonometric equation over 0 being less than or equal to A but less than 2pie 2cos(2A)=-2^1/2 Penny Nom lui répond.
	Using trig to find the height of a hill		2013-08-14
		Anna pose la question : From the top of a hill, the angles of depression of two successive milestones on a level road, which leads straight away from the hill, are 5degrees and 15degrees respectively. Fine the height of the hill. Suggestion: BE is drawn perpendicular to AD. Find BE, then BD, finally CD. Thanks :) Penny Nom lui répond.
	Practical uses of trigonometry		2013-08-06
		tharindu pose la question : use of trigonometry Penny Nom lui répond.
	The angle of elevation of the sun		2013-07-03
		Maurice pose la question : A vertical pole with a length of 7m cast a shadow with a length of 5m. Calculate the angle of elevation of the sun and include a diagram. Penny Nom lui répond.
	A kennel for a beagle		2013-06-03
		david pose la question : Hi, I'm building some beagle kennels and I am in need of help with an angle problem. I need to place a roof on my kennel with a drop of 2inches across 3ft 10inches. the posts on the right side will be 5ft and the post on the left will be 4ft 10in. the posts are 4x4 and the space to be covered is 3ft 10in from the outside of the 4x4. Please help, thanks. Penny Nom lui répond.
	Inverse trig functions		2013-05-19
		ky pose la question : hello, so iv'e been asked to draw a triangle with sides of 3, 4, and 5. And find the measure of all three angle using sin-1, cos-1, tan-1. I got really confuse, I'm taking the SAT pretty soon and it would be great to get this... THANX Penny Nom lui répond.
	(4- 4cos^4 x)/(sin^2 x)		2013-05-18
		Agnes pose la question : How I can solve this question : Simplify (4- 4cos^4 x)/(sin^2 x) and write in terms of sin x Penny Nom lui répond.
	siin (A) and sin (A/2)		2013-05-09
		shanaia pose la question : given that sin A=4/5 and A is obtuse.find sin (A/2) Penny Nom lui répond.
	Find the height of the tower		2013-04-28
		nombulelo pose la question : the shadow of a tower,when the angle of elevation of the sun is 30 degrees is found to be 40 meters longer than when it is 45 degrees. Find the height of the tower Penny Nom lui répond.
	A cone problem		2013-04-14
		Courtney pose la question : Hello, I am having difficulty solving this cone problem. The biggest challenge I have is figuring out what angle they are talking about: The angle at the base of a cone is 34.5 degrees. Find the diameter of the cone at point on the edge of the cone 26cm from the tip. Penny Nom lui répond.
	A shortest distance problem		2013-03-28
		LYNDELL pose la question : I have a right triangle and know the length of all sides. How do I calculate the shortest distance from the vertex of the 90 degree angle to the hypotenuse? Penny Nom lui répond.
	Trigonometry		2013-03-23
		Tizoc pose la question : I am in a trig class and I have a conflict. When solving the length of a side, I know what trig function to use, but I do not know what angle to use in a calculator. To make this a little more understandable, if I have all the angles available in a right triangle and I use the tangent function, how do I know what to use? Heres what I do not know what to put in my calculator: Tan(?) Thanks in Advance! Penny Nom lui répond.
	Solve sin 3x = -0.1254 with x between o and 360 degrees		2013-02-21
		David pose la question : sin 3x = -0.1254 0 Harley Weston lui répond.
	Solve sin 3x = -0.1254 with 0		2013-02-21
		David pose la question : sin 3x = -0.1254 0 Harley Weston lui répond.
	A trig word problem		2013-02-18
		Amy pose la question : Susan notices an unusual rock formation at an angle of 30 degrees to the right of her direction of travel as she is white water rafting. as she continues in a relatively straight path for 20 m, the rock formation appears to be at 45 degrees to the right. she cotninues until the rock formation is directly to her right. how far is she fromt he rock formation? Penny Nom lui répond.
	The height of an aerial		2013-02-12
		ASIT pose la question : A vertical aerial stands on a horizontal ground. A surveyor positioned due east of the aerial measures the elevation of the Top as 48 degree. He moves due south 30metre and measure the elevation as 44 degree. determine the height of the aerial Penny Nom lui répond.
	The fourth side of an irregular polygon		2013-02-01
		Emran pose la question : I have a irregular polygon. I know 3 of the 4 sides, and 2 of the angles. A-B is 285, B-C is 149, and C-D is 310. Angle B is 135 degrees. and Angle C is 45 degrees. Is there a formula to solve for the final side? Thanks. Penny Nom lui répond.
	A boy walks 3km due east and 4km due north		2013-02-01
		Kayode pose la question : Question from Kayode A boy walks 3km due east and 4km due north. Find the bearing of the final point and the distance of the final position from the starting point. Harley Weston lui répond.
	Solve 2sin(2(theta))+sqrt(3)=0		2013-01-19
		Kaitlyn pose la question : how do you solve 2sin(2(theta))+sqrt(3)=0 with the interval [0,2pi) Penny Nom lui répond.
	A shed roof		2013-01-12
		christine pose la question : A roof on a shed is 7.3 ft wide has an incline of 20 degrees what is the height? Penny Nom lui répond.
	A trig identity		2013-01-04
		Tehmas pose la question : Prove sinC+sinD=2sin(C+D/2)cos(C-D/2) Harley Weston lui répond.
	The angles of elevation and depression		2012-12-03
		Chelsey pose la question : a person on a balcony of one building looks towards a second building. if the angle of elevation to the top of the second building is 25 degrees, the angle of depression to the bottom of the second building is 17 degrees, and the balcony of the first building is 22 feet above the ground, what is the height of the second building? Penny Nom lui répond.
	Practical uses of trigonometry		2012-11-11
		Michael pose la question : Where can I find books or information on real life function of sine and cosine? Penny Nom lui répond.
	The derivative of y = sin (30º + x)		2012-11-07
		Saskia pose la question : derivative of y = sin (30º + x) Harley Weston lui répond.
	My compass was off by 8 degrees		2012-10-30
		Oscar pose la question : If I walked 620' and my compass was off by 8 degrees how many feet from my heading was I? Thank You Penny Nom lui répond.
	A label to cover a plastic cup		2012-10-23
		Kevin pose la question : I'm trying to make a label to cover the entire outer area or a plastic cup. I know there must be a way to figure out the dimensions needed, but I can't seem to figure it out. The circumference of the bottom of the cup is 21.4cm and the circumference at the top of the cup is 29.8cm. The cup is 14.5cm tall. What should the height of the arc from the plane connecting the two ends of the 21.4cm arc. I attached a diagram where x is the value I'm looking for. I'm guessing there is some simple relationship between the length of a line and the arc needed to turn that line into a perfect circle, but I don't know what it is. Can you figure this out and share it with me? Thanks. -Kevin Penny Nom lui répond.
	A tank with an inner walled compartment		2012-10-12
		don pose la question : I have a tank 20 feet diameter, 19' 8" tall with an inner walled compartment that has a 7' 6" radius arc with in the tank. I need to figure out the volume of the inner area and the volume of the larger area. Harley Weston lui répond.
	The height of a building		2012-09-08
		Lin pose la question : How do surveyors determine a height of a building 150 feet away with an observation angle at 40 degrees? What is the elevation of that top floor? Penny Nom lui répond.
	Making a wind sock		2012-08-28
		John pose la question : I am trying to build a wind sock and need to be able to lay the shape out on cloth. I need the wind sock front opening (diameter) to be 3 1/2" and the rear opening diameter to be 1". The windsock needs to be 9 1/2" long. I tried using the example of the person trying to make a crayfish trap but got confused and could not figure out my numbers. Any help would be greatly appreciated. Thanks John Penny Nom lui répond.
	A tapestry rod on a curved wall		2012-08-14
		Marlyn pose la question : I have a curved wall with a radius of 6'. I am trying to have a 36" rod made to hang a tapestry and need to figure out the degree measure of the arc. Can you help me please? Penny Nom lui répond.
	The height of an isosceles triangle		2012-07-10
		ken pose la question : I am trying to determine the various heights of an isosceles triangle, if each has the same base dimension and varies in the degree of the base (equal) angles. What is the method to do this? As an example, of the base is 10, and the two equal angles are each 45 degrees, what is the height? With the same base (10), but with the two equal angles at 60 degrees, what is the height? And with the same base (10) and the two equal angles at 75 degrees, what would be the height? I know how to calculate the degrees of the third angle (add the degrees of the known angles, and subtract from 180); but am unsure if that is needed for figuring the overall height. And to be clear; I am not looking for the length of the sides of the triangle, but the height from the base to the top point. Thank you! Chris Fisher lui répond.
	A 10 inch circle using 2x4s		2012-05-19
		Ralph pose la question : I want to form a 10" circle with 4"high pieces of 2 x4's. If each 2x4 piece sit next to each other,What degree would I have to cut each side of the 2x4's, and how many would I need to form a 10 inch circle. I know there is a formula for this out there somewhere. Harley Weston lui répond.
	Two golf drives		2012-05-14
		peter pose la question : If a golf drive travels 250 yards with a perfectly perpendicular hit, what is the length of the base, if a second golf drive is off line by one degree? Penny Nom lui répond.
	cos(theta/30) = 1		2012-05-14
		Hope pose la question : cos (theta / 30 = 1 I am very confused as to how to solve it. Can you help? Penny Nom lui répond.
	The derivative of 2sin cubed x - 3 sin x		2012-03-25
		holly pose la question : suppose f(x) = 2sin cubed x - 3 sin x show that f 1(x) = -3 cos x cos 2x Harley Weston lui répond.
	Angle measures		2012-03-21
		jogiboy pose la question : how can i get the sine theta if the given is 3.14/3 Penny Nom lui répond.
	Tangent of theta		2012-01-17
		stahl pose la question : explain what the 'tangent of theta' means. Draw and label a diagram to help with your explanation. Harley Weston lui répond.
	A circle inscribed in a regular octagon		2012-01-16
		Eric pose la question : I have a circle inscribed in a regular octagon. How do I determine the length of one side of the octagon if I know the radius of the circle (2.75 inches) ? p lui répond.
	The radius of a circle		2012-01-12
		Janie pose la question : Find the radius of a circle knowing that a chord of 24.6 inches has a corresponding arc of 70°. Penny Nom lui répond.
	A trig identity		2012-01-08
		Joe pose la question : Prove this Trig. Identity : ((cos2θ + sinθ-1) / tanθ ) + sin2θ = cosθ Penny Nom lui répond.
	The height of a tower		2012-01-06
		trevor pose la question : A tower is on the top of a hill. It is 2,400 feet from an observer to a point directly under the tower and at the same elevation as the observer. The angle of elevation from the observer to the base of the tower is 15 degrees and to the top of the tower 23 degrees. How tall is the tower in feet? Compute your answer within one foot. Penny Nom lui répond.
	The height of a flagpole		2011-12-07
		Grail pose la question : at a certain point the angle of elevation of the top of a flagpole which stands on a level ground is 35 degree. 75 ft. nearer the pole, the angle of elevation is 50 degree. How high is the pole Penny Nom lui répond.
	What is the altitude of the balloon?		2011-12-04
		C pose la question : Chelcy and Jorgeare 2.32 miles apart. The observe a hot air balloon directly overhead between them Chelcy's angle of elevation is 28 degrees. Jorge's Angle of elevation is 37 degrees. What is the altitude of the balloon? Penny Nom lui répond.
	Solve for theta if 8cos^2 theta-3=1		2011-12-02
		Katherine pose la question : Hi, I have just learned to solve trigonometric problems for theta and have one specific question in order to find the solutions to my homework. I will use one example for this question. If I have 8cos^2 theta-3=1 I first divide by 8 and get cos^2theta=3/8 then I have cos theta= plus or minus the square root of 3/8 Then I assume that I plug in inverse cos (the square root of 3/8) to my calculator. How do I find the four solutions (we are typically supposed to find four, I believe?) Can you help me with finding the solution to this problem? Thank you! Penny Nom lui répond.
	The height of a flag pole		2011-11-21
		Micah pose la question : A flagpole stands vertically at the edge of a roof of a building 200 ft high. the angle of elevation of the pole from a point 100 ft from the bottom of the building is 67 degrees. Find the length of the pole in meters. Penny Nom lui répond.
	sin A/1+cos A + 1+cos A/sin A = 2cosec A		2011-10-20
		Neeraj pose la question : sin A/1+cos A + 1+cos A/sin A = 2cosec A Penny Nom lui répond.
	The height of a building		2011-09-09
		Sally pose la question : A building's angle of elevation from a point on the ground 60 ft. from its base is 32 degrees. What is the height of the building? Penny Nom lui répond.
	Find the distance from the ladder's base to the wall		2011-08-19
		Donna pose la question : A 16 foot ladder leans against a wall at a 67 angle of elevation I need to find the distance from the ladder's base to the wall Penny Nom lui répond.
	A stained glass lamp		2011-07-25
		Guy pose la question : Like Kay, I also work in stained glass, but in 3-dimensions. I am frequently asked to replicate lamp shades in stained glass where the diameter of the top is different (narrower) from the diameter of the bottom (which is wider). Some people want 5, 6, 7, 8, 10, 12, 16, ,,, n-sided shades. Is there a formula I can use to determine the width of the sides using the angle, if I remember correctly, I think it's called theta. In other words, is there a formula where I can plug in the angle which describes the arc of the circle. For instance, if someone asks for a 7 sided shade, plugging in 51.43 (360/7). I could then use that to determine the width at the top and bottom rings to create the appropriate trapezoids. I've visited a few sites so the formula looks like its a function of sin & cos but they are presented like proofs for teaching. Your site appears to want to actually answer questions without making the inquirer feel stupid. Harley Weston lui répond.
	The length of a belt around three pulleys		2011-05-18
		Grant pose la question : I need to calculate the belt length around these pulleys, please can you help or refer me? Known variables D - Large Pulley Diameter d - Small Pulley Diameter c - Center Distance between D and d T - Tension Pulley Diameter x - Horizontal Distance between T and d' Centers y - Vertical Distance between T and d's Centers I need to calculate the belt length around these pulleys. Kind Regards, Grant Harley Weston lui répond.
	cos(x) = -1/(square root of 2)		2011-04-27
		Shelby pose la question : Find exact value of x for 1 <(or equal to) x < 2pi a) cos(x) = -1/(square root of 2) Penny Nom lui répond.
	Two trig equations		2011-04-20
		Tony pose la question : find the value of pi in the following: sin pi= cos(pi + 40) sin(80 - pi)=cos pi Penny Nom lui répond.
	-1 = -sin^2x - cos^2x		2011-04-11
		veronica pose la question : I need the solutions for -1 = -sin^2x - cos^2x Penny Nom lui répond.
	Real-life applications of trigonometry		2011-04-10
		Angela pose la question : I am a teacher and I desire to show the students the real-life application of trigonometry. Of course, one application is to use a clinometer and find the heights of various things. However, I am trying to provide a real-life scenario which also answers the question "why" the height of the object needs to be found. Not being an engineer, I do not know the specifics examples, but I want my information to be accurate and my example to to be as real-life as possible. I mean, I can say that someone wants to know the height of a flagpole; however, I also want to answer the question "why" they want to know this. I would like to give an actual real-life scenario. Do you know of some? Thanks! Penny Nom lui répond.
	sin x = -0.25		2011-03-29
		Wayne pose la question : How do you solve for x in the equation sin x = -0.25 the answer is 3.394 and 6.030 but I don't know the steps they used to calculate this Penny Nom lui répond.
	A true or false trig question		2011-03-24
		Abeth pose la question : True or False: Since cot (theta) = cos (theta)/sin (theta), if cot (theta) = 1/2, then cos (theta) =1 and sin (theta)=2. My answer before was true, but not my answer is false. Can you give me a solution on this matter. thanks. Penny Nom lui répond.
	Prove sin x = sin (pi - x)		2011-02-15
		Janet pose la question : Prove sin x = sin (pi - x) Penny Nom lui répond.
	A fence around a water tank		2011-02-01
		Heath pose la question : I am building a fence around a water tank. the fence is to be in the shape of a normal octagon. The tank has a circumference of 57 ' 6''. I would like the fence to be 3 ft from the tank at the skinny point . How would I calculate(for the simple guy) where to set each of my 4x4 posts at the 8 corners. Any help would be greatly appreciated. Harley Weston lui répond.
	tanθ=1.192		2011-01-15
		Adori pose la question : Use a calculator to approximate two values of the θ (0 ≤θ≤2π) that satisfy the equation. a) tanθ=1.192 I do not understand how to find the second value of θ. Harley Weston lui répond.
	Tan(x+pi)-tan(pi-x)=2tan(x).		2011-01-09
		Steven pose la question : Verify the identity: Tan(x+pi)-tan(pi-x)=2tan(x) Penny Nom lui répond.
	[sec^2x]*[sec^2x]		2010-12-16
		Hari pose la question : [sec^2x]*[sec^2x]=...? Penny Nom lui répond.
	How far must the pitcher travel to get to the ball?		2010-11-04
		ken pose la question : A baseball player bunts a ball down the first base line. It rolls 35ft at an angle of 26 degrees with the first base path. The pitchers mound is 60.5 ft from the plate. How far must he travel to get to the ball. Penny Nom lui répond.
	A problem that can be solved using trigonometry and geometry		2010-10-29
		xolani pose la question : In your neighbourhood find a problem that can be solved using trigonometry and geometry. write a report on the problem and how you solved it. the report should contain: a) a clear description of the problem, accompanied by a diagram and all necessary measurements. b) a solution to thje problem, showing all calculations. c) proper theorems and rules must be used as part of the solution. Robert Dawson lui répond.
	sin14.5/a = sin150/280		2010-10-26
		ken pose la question : how do you do the steps to this equation. sin14.5/a = sin150/280 the text book answer is 140.21 miles ,but how do the steps? Penny Nom lui répond.
	A building and a flag pole		2010-09-09
		paul pose la question : A flag pole and a building stand on the same horizontal level. From the point p at the bottom of the building,the angle of elevation of the top t of the flag pole is 65 degrees. From the top q of the building the angle of elevation of the point t is 25 degrees.If the building is20 meters high. Calculate the distance pt Penny Nom lui répond.
	The shadow of a building		2010-07-28
		vera pose la question : building casts a shadow 210 ft. long,40 degree angle.How tall is the building? Penny Nom lui répond.
	An octagon shaped bench		2010-07-09
		rob pose la question : i am trying to build a octagon shaped bench to fit inside a 69 inch round hot tub so that the tip of each point touches the edge of the circle where it will be fastened. Stephen La Rocque lui répond.
	The capilano suspension bridge		2010-06-03
		nida pose la question : the capilano suspension bridge in north vancouver is the world's highest footbridge of its kind. the bridge is 140m long . from the ends of the bridge the angles of depression of a point on the river under the bridge are 41 degrees and 48 degrees. how high is the bridge above the river to the nearest metre Penny Nom lui répond.
	Integration of sin^3 (2x)		2010-05-29
		ascher pose la question : how do you integrate this equation ∫ sin^3 (2x) dx Robert Dawson and Penny Nom lui répond.
	The altitude of a triangle		2010-05-08
		kylie pose la question : the vertex angle of an isosceles triangle is 57 degrees 24 minutes and each of its equal sides is 375.5 feet long. find the altitude of the triangle Penny Nom lui répond.
	A trig equation		2010-04-28
		Steve pose la question : 2cos^2(X)-2sin^2(x)+1=0 Harley Weston lui répond.
	cos(x) = sin(x - 1)		2010-04-28
		alex pose la question : In the equation cos x = sin x-1 for -pi/2 A: solve for x graphically B: solve algebraically and prove the solution is correct. Alex Penny Nom lui répond.
	The height of a flag shaft		2010-04-25
		Sarah pose la question : A man standing 20metres away from a tower observes the angles of elevation to the top and bottom of a flag shaft standing on the tower as 62degrees and 60degrees respectively. Calculate the height of the flag shaft.' Penny Nom lui répond.
	Solving a trig equation		2010-04-21
		Jason pose la question : Please Help! My question is : Find all of the solutions to sin(x/2)+cosx-1=0 Penny Nom lui répond.
	Polar coordinates		2010-04-14
		Lan pose la question : Given the rectangular equation (x^2)+2x+(y^2)+y=0, find the polar equation. Harley Weston lui répond.
	Vapor trails		2010-04-12
		Frank pose la question : I'm not sure if this is a proper question to ask so if I have misdirected my question I apologize and no response is expected. I am trying to figure out a way to measure vapor trails from my back yard in Phoenix Arizona. If I used a compass and spread each point of the compass to the start and finish of the vapor trail I would have the angle of an isosceles triangle. The other two angles would be identical. The height of from the inverted base of the triangle to my standing spot on the ground would be about 35,000 feet. I'm thinking that there should be a way to figure out the length of the inverted base (vapor trail) but I'm devoid of mathematical skills and can't seem to figure out how to do this. Is it possible to figure out the length of a vapor trail using this method or do you have an easier way to accomplish the task? Any help you could offer would be most appreciated. Thanks....Frank Harley Weston lui répond.
	A trig identity		2010-03-27
		Anne pose la question : Prove: (2tanx-sin2x)/2sin^2x=tanx Penny Nom lui répond.
	The height of a hill		2010-03-26
		Amber pose la question : A surveying team determines the height of a hill by placing a 12-foot pole at the top of the hill and measuring the angles of elevation to the bottom and to the top of the pole. They find the angels of elevation. Describe how to find the height of the hill. Penny Nom lui répond.
	A radio tower		2010-03-26
		Alex pose la question : The height of a radio tower is 450 feet, and the ground on one side of the tower slopes upward at an angle of 10 degrees. How long should a guy wire be if it is to connect to the top of the tower and be secured at a point on the sloped side 110 feet from the base of the tower? Harley Weston lui répond.
	A 6m ladder is placed against a wall		2010-03-09
		Trevor pose la question : A 6m ladder is placed against a wall making a 56 degree angle with the ground. How far up the wall does the ladder reach? Harley Weston lui répond.
	A trig identity		2010-03-08
		Kim pose la question : I am having trouble proving this trig identity (sin^2 x + 2 cos x-1) / 2+cos x - cos^2 x = 1/ (1+ sec x) Penny Nom lui répond.
	The integral of X^3/the square root of 1-x^2 dx		2010-03-07
		William pose la question : The integral of X^3/the square root of 1-x^2 dx. Harley Weston lui répond.
	The other two sides of a right angle triangle		2010-02-09
		ayesha pose la question : how to find the other two sides of right angle triangle when length of one side and angle of other side is given i.e 45 Penny Nom lui répond.
	The height of a roof		2010-01-31
		carl pose la question : Width of my roof I am building is 5M at baseline, and the pitch is 40%. What will the height be, and how can I work this out in the future. Penny Nom lui répond.
	A trig identity		2010-01-24
		Natalie pose la question : hi, i need help proving the following trig identity. i cant seem to figure out how to do it. thanks so much. (1+sin2x)/cos2x = cos2x/(1-sin2x) Penny Nom lui répond.
	A trig problem		2010-01-22
		vinton pose la question : ok there is a triangle labled q, p, r......the three towns p, q, r are such that the bearing of p from q is 070 degrees. r is 10 km due east of q and pq = 5km. (i) calculate correct to one decimal place, the distance of pr. (ii) given that angle qpr 142 degrees, state the bearing of r from p Penny Nom lui répond.
	A trigonometric equation		2010-01-21
		Laura pose la question : Find the exact solution for sin4t + √3sin4t = 0 for t when (o ≤ t ≤ π Harley Weston lui répond.
	A trig identity		2010-01-21
		Alesia pose la question : How to prove Csc(A+B) = (csc A Csc B)/ (Cot A+ Cot B) Penny Nom lui répond.
	How far apart are the two girls?		2010-01-18
		benny pose la question : Debby and john are looking up at their house from the backyard. From Debby's point of view, the top of the house is at an angle of elevation of 40 degrees From Johns point of view, directly closer to the house, it is 60 degrees. The house is 15m high. How far apart are the two girls? Robert Dawson lui répond.
	Trigonometry and picture hanging		2010-01-13
		george pose la question : The top of a picture 1m high 0.8m from the ceiling. At a point on the ceiling directly in front of the picture, we wish to install a light so that the angle subtended by the picture equals to the angle of depression of the top of the picture. How far out from the wall should the light be installed? Penny Nom lui répond.
	A trig identity		2010-01-05
		Christine pose la question : I need help with this whole paper here is one problem csc^2x-cot^2x/1-sin^2x=sec^2x by the ^2 i mean squared pleease Penny Nom lui répond.
	tan x= cos 100		2010-01-04
		Ruby pose la question : Given that tan x= cos 100 and x=0-180. calculate the value of x. (All measurements in degrees) Robert Dawson lui répond.
	The height of a mountain		2010-01-02
		Aye pose la question : In order to decide the height of a remote mountain peak T one measures from two points A and B the angles u and v where the lines AT and BT made with the Horizontal plane respectively. From B, which lies 2400 m from A, one can see A and T by the same point of the compass. Find the height of a mountain peak, if A and B are known to be 950 m and 875 m above sea level respectively, as well as u = 43,8 degree and v = 25,2 degree. Aye Harley Weston lui répond.
	A trig question		2009-12-15
		A trig question pose la question : Hey, my name is Candle I'm in academic math10 and am stuck on my trig... one question I thought I had right because i used the cosine law I got wrong and can't figure out why... here's a copy of the question. (i guessed it was D... but my teacher said it's B) Thanks Candle Robert Dawson lui répond.
	A telephone pole on a slope		2009-12-14
		Marissa pose la question : A 10 meter telephone pole casts a 17 meter shadow directly down a slope when the angle of elevation of the sun is 42 degrees. Find the angle of elevation of the ground. Its a law of sines problem. Penny Nom lui répond.
	f(x)=x+2sinx		2009-12-12
		amroziz pose la question : for which values of x does the graph of f(x)=x+2sinx have horizontal tangent Harley Weston lui répond.
	The height of an isosceles triangle		2009-12-06
		Carl pose la question : What is the height of an isosceles triangle if its base is 12cm, and its base angle is 72degrees? Penny Nom lui répond.
	sin x / 1+ cos x = csc x - cot x		2009-11-18
		Mansi pose la question : i need a hint on how i could prove the following identity: sin x / 1+ cos x = csc x - cot x Harley Weston lui répond.
	A truncated cone		2009-11-11
		Lucian pose la question : I need to calculate the bottom inside diameter of a truncated cone. The top insdie diameter is 1450mm. The material is 6mm thick The cone angle is 20 degrees The slant length is 152mm I would like a formula so that I can build a spread sheet Penny Nom lui répond.
	y = sin(x) + 3		2009-11-10
		Kapilan pose la question : When graphing trigonometric functions like SIN and COSINE does f(x)=x squared equal to SIN or COSINE Also what is the range, domain, period and ampliltude for y=sin@ + 3 Harley Weston lui répond.
	sinA + cosA = 1		2009-11-06
		Nazrul pose la question : What is the solution of sinA+cosA=1 where A is an acute angle? Will A=0 degree be included in the solution? Please explain. Harley Weston lui répond.
	A minute hand		2009-11-05
		Pardha pose la question : A minute hand of table clock is 3cms long. How far its tip move in 20 minutes Penny Nom lui répond.
	Cutting a pipe at an arbitrary angle		2009-10-24
		Carol pose la question : I have read your article on cutting pipe,etc. at a 45 degree angle. I need to develop an equation and pattern for cutting any size pipe (3" to 7") to any degree. I don't understand how to transfer the wave pattern to graph paper. Thanks. Harley Weston lui répond.
	Find the intersection of y=x-1 and y=sin(x)		2009-10-10
		Usama pose la question : There are many modern calculators and softwares that can plot the functions. I have two very simple equations y=x-1 and y=sin(x), if i draw them manually on paper i can not get the accurate value. But i think a computer can easily draw perfect straight and curve lines so it should be easy to find the intersection point of two lines. Is there any way or software that can tell the exact value of intersection point of two lines? Robert Dawson and Harley Weston lui répond.
	How high is the ledge?		2009-10-03
		gabby pose la question : Standing on a ledge, there is a boat 25 degrees below you. The boat has a 1,000ft. tower. If the angle of elevation to the top of the tower is 15 degrees, how high is the ledge? Stephen La Rocque lui répond.
	Hexadecagon		2009-09-20
		Rick pose la question : Is there an easy way to figure the even side lengths of a Hexadecagon in layman's terms, so I know how long to cut the exterior support boards for my pool deck. The pool is a 16' diameter Hexadecagon and my Wife wants a 4' wide splash deck all the way around which would make the outside 24' in diameter. Chris Fisher and Harley Weston lui répond.
	How deep is the hole?		2009-08-25
		Scott pose la question : If I have a hole three foot in circumference that runs at a 15degree angle from the surface and continues for a length of 100 feet, how deep would the hole be at 100 feet? Penny Nom lui répond.
	The leaning tower of Pisa		2009-08-09
		MF pose la question : Would you have any idea how the 'latitude of 44 degrees N" has anything to do with this question and how I would apply it? The leaning tower of Pisa leans toward the south at an angle of 5.5 degrees. One day near noon its shadow was measured to be 84.02 m long and the angle of elevation from the tip of the shadow to the top of the tower was measured as 32.0 degrees. To answer the question, assume that the tower is like a pole stuck in the ground, it has negligible width. Also, it is important to know that Pisa Italy is at a latitude of approx 44 degrees North because this affects the direction of the shadow.) Stephen La Rocque lui répond.
	sinA-cosA=1		2009-07-30
		Nazrul pose la question : How can I solve sinA-cosA=1 where 0 degree<=A<=90 degree. Thank you. Harley Weston lui répond.
	A trig identity		2009-07-10
		sam pose la question : I need to prove: tan x (cot x + tan x) = sec2 x (the "sec2" is "sec squared") I am totally stuck!! Thanks! Stephen La Rocque and Harley Weston lui répond.
	A trig identity		2009-06-30
		sumayya pose la question : prove that sin A (1+tan A)+cos A (1+cot A)= sec A+ cosec A Robert Dawson lui répond.
	Finding an Acute Angle using Trigonometric Identities		2009-06-29
		Nazrul pose la question : How can I find the value of A if sinA-cosA=1 , where A is an acute angle. Stephen La Rocque lui répond.
	Ground Velocity of an Aircraft		2009-06-07
		Anna pose la question : An aircraft is flying at 180km/hr and there is a northerly wind of 35km/hr. The pilot steers the aircraft at an angle of 40 degree east of north. Which direction (in degrees east of north) is the aircraft travelling over the ground? Stephen La Rocque lui répond.
	How long are the rafters?		2009-06-03
		Tina pose la question : An architect designs a house that is 12 m wide. The rafters holding up the roof are equal in length and meet at an angle of 70 degrees. The rafters extend 0.3 m beyond the supporting wall. How long are the rafters? Penny Nom lui répond.
	sin x/ 1+cos x = 1-cos x/ sin x		2009-05-30
		rita pose la question : prove: sin x/ 1+cos x = 1-cos x/ sin x Stephen La Rocque lui répond.
	Two ships and a lighthouse		2009-05-27
		Chelsey pose la question : I have a question in regards to how do I know when to use tangent or cosine when determining angles. The question is: Looking north from the observation deck of a lighthouse 60 m above the sea, a lighthouse keeper sees two ships. The angles of depression to the ships is 5 degrees and 10 degrees. How far apart are the ships? I don't understand which one to use when solving the equation. Harley Weston lui répond.
	sin54 cos36/cos18 - 2cos36 -2sin18 = ...		2009-05-23
		citra pose la question : sin54 cos36/cos18 - 2cos36 -2sin18 = ... thank you very much.. Stephen La Rocque lui répond.
	Application of Derivatives of Trig Functions		2009-05-21
		Alannah pose la question : I have a word problem from my Calculus textbook that I can't figure out. Triangle ABC is inscribed in a semicircle with diameter BC=10cm. Find the value of angle B that produces the triangle of maximum area. I am supposed to set up an equation for the area of the triangle A=b x h/2 using Trig functions based on angle B to represent the base and height but I'm not sure how to do this when the side length given is not the hypotenuse. Janice Cotcher lui répond.
	4cos^2 (3x) + 3sin (3x) = 1		2009-05-05
		Cheryl pose la question : Find all solutions of the following equation and show how to do this algebraically. 4cos^2 (3x) + 3sin (3x) = 1 Harley Weston lui répond.
	Practical trigonometry		2009-05-04
		Lori pose la question : I am an ex-math major turned home-schooling parent. I would desperately like to find a word-problem based trigonometry book for my 17-year old son. I don't want graphing or other gobbledy-gook that he'll never use. Does such a thing exist? Robert Dawson lui répond.
	A two goat problem		2009-04-27
		Michael pose la question : if you have a goat tied to a pole at one corner of a square paddock with one length of a side being 24m. what length must the rope be for the goat tied up to graze half the paddock? and if another goat is placed on the opposite corner and same length what is the amount of area they share grazing ? Stephen La Rocque and Penny Nom lui répond.
	(1+2sinxcosx)/(sinx+cosx) = sinx+cosx		2009-04-23
		Katie pose la question : Solve this identity: (1+2sinxcosx)/(sinx+cosx) = sinx+cosx Thank you ! Stephen La Rocque lui répond.
	A vertical radio tower is located on the top of a hill		2009-04-21
		Rafael pose la question : A vertical radio tower is located on the top of a hill that has an angle of elevation of 10 degrees. A 70-foot guy wire is attached to the tower 45 feet above the hill. a. Make a drawing to illustrate the situation b. What angle does the guy wire make with the side of the hill? c. How far from the base of the tower is the guy wire anchored to the hill? What confuses me about this problem is the visual situation. Isn't the angle of the guy wire with the side of the hill the same as the angle of elevation? And if not, then how is one supposed to find the other angles without any more information? Harley Weston lui répond.
	cos2x = sinx		2009-04-19
		stacey pose la question : solve the equation cos2x = sinx for 0 < x < 2 pi giving the answer in terms of pi. Harley Weston lui répond.
	2sinB=3tanA		2009-04-10
		Xanathax pose la question : ABC is a right-angled triangle. 2sinB=3tanA. Calculate the measure of angle A. Penny Nom lui répond.
	A ladder against a wall		2009-04-08
		Jessica pose la question : The angle of elevation of a 15 ft. ladder is 70 degrees, find out how far the base of the ladder if from the wall. Penny Nom lui répond.
	The perimeter of a pentagon		2009-04-07
		Malysa pose la question : A pentagon has an area of 1400 cm squared. Determine its perimeter. Harley Weston lui répond.
	An arched or round top window		2009-04-07
		Dale pose la question : I need a formula to figure the lineal footage of trim require to trim an arched or round top window. The variables that I have consist of the width of the window the height of the arc and the radius. Harley Weston lui répond.
	2sin^2x-sinx=0		2009-04-02
		Jose pose la question : 2sin^2x-sinx=0 and i know the answer im just having trouble figuring out how it went from the original equation to sin(x)2sin(x)-1=0? Harley Weston lui répond.
	The height of a mountain peak		2009-03-23
		james pose la question : Can you please help us (my son Jim geometry) out with this problem, we cannot seem to find the correct method of solving, not sure how to solve the scalene triangle with what is given...if that's the correct method?? Can you please explain how this is solved!! Thank you so much, Jim and son ! Harley Weston lui répond.
	An impossible trig problem		2009-03-14
		Alisha pose la question : If csc theta = 3 and sec theta = square root of 3, what are the values of tan theta and cos^2 theta? Harley Weston lui répond.
	sin x + cos x = x		2009-03-06
		Ashley pose la question : For what values of x is the following true: sin x + cos x = x Robert Dawson lui répond.
	For what x is cos x is greater than root 3 over 2?		2009-02-25
		Robert pose la question : cos x is greater than root 3 over 2 Restrictions: between 0 and 2pi Harley Weston lui répond.
	cos 2x = 2 sin x		2009-02-25
		Bobby pose la question : cos 2x = 2 sin x Harley Weston lui répond.
	Trig functions without geometric data		2009-02-24
		bob pose la question : I do not understand how it is possible to find the sine, cosine, or tangent of an angle if there is no hypotenuse, opposite or adjacent side?! Robert Dawson lui répond.
	Find all values of 2sin4x + (Sqrt)3 = 0, in [0, 2pi]		2009-02-21
		Sam pose la question : Find all values of 2sin4x + (Sqrt)3 = 0, in [0, 2pi]. Harley Weston lui répond.
	Angle of depression		2009-02-18
		Meeka pose la question : An aircraft flying at an altitude of 2000m is approaching an airport. If the angle of depression of the airport is 5 degrees, what is the distance from the plane to the airport measured along the ground? Round your answer to the nearest tenth of a kilometer. Robert Dawson lui répond.
	A trig limit		2009-02-05
		Samantha pose la question : lim x-> 0 ( ( r*cos(wt +h) + r*cos(wt) )/ h ) Where r & w are constants. Harley Weston lui répond.
	A trig limit		2009-02-05
		Kathy pose la question : Hi! I was just wondering how to do this question: lim 1-cos2x/xsinx as x approaches 0 Thanks, Kathy Penny Nom lui répond.
	The grade of a roadway		2009-01-26
		black pose la question : A highway that has a 6% grade rises 6 ft vertically for every 100 ft horizontally. Which trigonometric ratio is being used in reporting the 6% grade? Explain why Stephen La Rocque lui répond.
	A trig problem		2009-01-18
		Conor pose la question : sinx= 6/10 ; Find the exact value of cos(squared) x / 1-tanx Harley Weston lui répond.
	A applied math trig problem		2009-01-13
		Simon pose la question : I wish to find all the answers for the following equation over the interval (0,1): cos^2(pi * n^x) + cos^2(pi * n^(1-x)) - 2 = 0 where n is any integer > 0 Robert Dawson and Harley Weston lui répond.
	Trig identities		2009-01-05
		Michael pose la question : 1) Determine if the following is an identity. If it is, prove it, If it isn't state it. tan x + cot x = sec x * csc x and 1 - (cos^2) x = 1+ (cot^2) x Robert Dawson and Harley Weston lui répond.
	Pouring angles for a crucible		2008-12-20
		Richard pose la question : I am trying to work at pouring angles and volume left in during pouring a crucible, The crucible is cylindrical and flat bottomed. I know the diameter, radius and volume of the crucibles. and the volume of liquid going into it. So lets say the crucible is only half full firstly I need to work out the angle just before its going to pour. ( I can work this out as long as there is a certain volume of liquid if its not enough I cant do it) Now the problem I also need to work out how much I should tilt the crucible to allow a certain amount out and be able to do this untill the volume reaches 0 at 90' turn. This is where I am stuck. The reason for needing to be able to work this out is so i can develop a constant flow for example 10Kg of metal per second. Thank you very much for you time Harley Weston lui répond.
	Limit of a Trig Function		2008-12-06
		Berta pose la question : Evaluate limit xcsc2x/cos 5x as x goes to 0 ans is 2 but I get 1/2 x/sin2xcos5x = 2x/2sin2xcos5x= 1/2cos5x Penny Nom lui répond.
	How high is the flagpole?		2008-12-02
		michael pose la question : 100 m from the base of a flagpole the angle of elevation of the top of the flagpole is 7degree 16'12".how high is the flagpole Harley Weston lui répond.
	A trig identity		2008-11-25
		Jeff pose la question : i cannot prove this trigonometric identity. please help! (cos x)^3 – (sin x)^3 = (cos x –sin x) (1+cosxsinx) Chris Fisher lui répond.
	Sec(2x)		2008-11-23
		Evan pose la question : Prove that this is an identity... sec2x = sec^2x / 2 - sec^2x Harley Weston lui répond.
	How far are the boats apart?		2008-11-14
		dom pose la question : Two boats leave port at the same time. They leave at 150 degree angle. One boat travels at 10mph and the other at 20mph. After two hours how far are the boats apart? Penny Nom lui répond.
	A trig Identity		2008-11-13
		Rebecca pose la question : Question from Rebecca, a student: How do I prove:      1/sin@                csc@                -2sin@ ________      +       ______       =    _____ 1 + CSC@         1-1/sin@                 cos^@ Penny Nom lui répond.
	A barrel on its side		2008-11-13
		Dave pose la question : Question from Dave: How many gallons are left in a 36x60 in. barrel (laying on its side) and has 16 in. of gasoline left. I have attached a diagram. Harley Weston lui répond.
	A trig limit		2008-11-04
		Teri pose la question : Although I have this problem completely worked out in front of me I still cannot understand how it was done. The problem is: Find the limit. lim x->0 sin2x/tan7x. Harley Weston lui répond.
	A trig identity		2008-11-03
		Student pose la question : verify cos(2x)=(cot(x)-tan(x))/(cot(x)+tan(x)) Penny Nom lui répond.
	Sin(theta) = -3		2008-10-24
		jonathan pose la question : how can i solve this if the only given is sin theta= -3 tan theta= cos theta= cot theta= co secant theta= secant theta= can you teach me and show how to solve?? Stephen La Rocque lui répond.
	cos^2x - 3cosx = 1		2008-09-29
		Danielle pose la question : cos2x - 3cosx = 1 Penny Nom lui répond.
	How tall is the wall?		2008-09-29
		ash pose la question : you and bob are separated by a tall wall you stand 10 feet further from the wall than bob your angle of elevation is 37 degrees and his 44 degrees how tall is the wall? Penny Nom lui répond.
	Geometry with A Ladder Using Trig Functions		2008-09-20
		Please pose la question : A ladder makes an angle of 50 degrees with the ground. if the base of the ladder is 10 feet from the building, how high up the building does the ladder reach? i saw that someone else had a similar question, but we arn't using the pythagorean therom. we are using trig functions. Most of the problems we are doing is with the tangent. so this one probably is too. Penny Nom lui répond.
	Cutting a pipe at an arbitrary angle		2008-09-20
		John pose la question : from the original question Al asked about cutting a 200 diameter pipe in 45 degrees. can someone explain the math steps required to creating the graph. I am trying to do the same thing only using a 150 degree cut. Harley Weston lui répond.
	Cutting a pipe on a 45 degree angle		2008-09-12
		Bakshani pose la question : how do you a mark a pipe 5 inch diameter and cut it to form a 45 degree angel Stephen La Rocque lui répond.
	Angle of elevation		2008-09-09
		kristy pose la question : A man on the tenth floor of a building shouts down to a person on the street. If the angle of elevation from the street to the man in the building is 35° and the man in the building is 40 feet up, about how far away from the building is the person on the street? Penny Nom lui répond.
	The height of a tree		2008-09-09
		danice pose la question : At a certain time of day, the angle of elevation of the sun is 30°. A tree has a shadow that is 25 feet long. Find the height of the tree to the nearest foot. Penny Nom lui répond.
	Finding the Speed of a Truck		2008-09-08
		Rita pose la question : A state trooper is hidden 30 feet from a highway. One second after a truck passes, the angle theta between the highway and the line of observation from the patrol car to the truck is measured. (a) If the angle measures 15 degrees, how fast is the truck traveling? Express the answer in feet per second and miles per hour. Janice Cotcher lui répond.
	How far was the ship from the tower at 1:30 p.m?		2008-09-07
		sam pose la question : A passenger on a ship sailing north at 5.0 mph noticed that at noon a radio tower on land was due east of the ship. At 1:30 p.m., the bearing of the tower from the ship was S35degreesE. How far was the ship from the tower at 1:30 p.m. Stephen La Rocque lui répond.
	A surveillance satellite		2008-09-04
		Rita pose la question : A surveillance satellite circles Earth at a height of h miles above the surface. Suppose that d is the distance, in miles, on the surface of Earth that can be observed from the satellite. (a) Find an equation that relates the central angle theta to the height h. (b) Find an equation that relates the observable distance d and theta. (c) Find an equation that relates d and h. Penny Nom lui répond.
	A 30-60-90 triangle		2008-08-20
		ronie pose la question : finding the sin,tan,sec,cos and csc.given is square root of 3 over 2.the question are how to find that? Penny Nom lui répond.
	Solving for Shared Height of Two Right Triangles		2008-08-17
		Heidi pose la question : find the height of a triangle, which can be split into two right triangles, but the base (50m) is not split equally in half. one end of the base is 40 degrees, while the other is 30 degrees. Janice Cotcher lui répond.
	TRIG IDENTITIES		2008-08-17
		VINCE pose la question : HOW DO YOU SIMPLIFY THE FOLLOWING:- 2sin3(theta)cos3(theta)? Regards Harley Weston lui répond.
	Finding Angles in a Pyramid		2008-07-30
		Carla pose la question : A pyramid has its vertex directly above the centre of its square base. The edges of the base are each 8cm, and the vertical height is 10cm. Find the angle between the slant face and the base, and the angle between the slant edge and the base. Janice Cotcher lui répond.
	Trigonometric		2008-07-28
		kiran pose la question : In triangle , Sin@ = ? Penny Nom lui répond.
	A trig problem		2008-07-27
		Carla pose la question : PQRS is a rectangle. A semicircle drawn with PQ as diameter cuts RS at A and B. The length PQ is 10cm, and angle BQP is 30deg. Calculate the length PS. Stephen La Rocque lui répond.
	How many gallons of fuel still in the barrel?		2008-07-22
		Charles pose la question : I have barrel 6 feet long and 3 feet diameter that is laying on it's side with 5 inches of fuel, how many gallons of fuel still in barrel Penny Nom lui répond.
	Graphing Using Double Angle Identities		2008-07-16
		Hodan pose la question : the Question is: Describe how you could use your knowledge of Double angle formulas to sketch the graph of each function. Include a sketch with your description.A) F(x)=sin x cos x B)F(x)=2 cos(squared)x C) F(x)= tan(x) (divided) by 1-tan(squared) x Janice Cotcher lui répond.
	A trig exercise		2008-07-14
		Carter pose la question : let cos B = a, find cos 2B and sin 2B in terms of a and hence confirm that cos^2 (2B) + sin^2 (2B) = 1 Harley Weston lui répond.
	Domain & Range of a Periodic Function		2008-07-11
		Michelle pose la question : The depth, w metres, of water in a lake can be modelled by the function, w=5sin(31.5n+63) +12 where n is the number of months since January 1, 1995. Identify and explain the restrictions on the domain and range of this function. Janice Cotcher lui répond.
	How far is the ladder from the wall?		2008-07-10
		Al pose la question : a ladder is leaning against a wall at a 70 degree angle and the ladder is 20 feet tall...how far away is the ladder from the wall Penny Nom lui répond.
	Trigonometric equations		2008-07-09
		Carla pose la question : Hello, my problem is as follows: Solve the given equation for A, giving your answers in the interval from -180 to 180 4 sin A cos A + 1 = 2 (sin A + cosA) Harley Weston lui répond.
	sin(2x)/sin(3x)		2008-06-19
		matt pose la question : how does sin2x break down (not with identities) and how would sin3x be created. My prob. is sin 2x/ sin 3x and I want to know how the double(or triple angle) would break down. I want to be able to cancel out sins. Thanks! Harley Weston lui répond.
	tan(4a - b)		2008-06-12
		A student pose la question : hi guys just a quick help on question needed thanx if tan a = 1/5 and tan b = 1/239 find value of tan(4a-b) thanks alot in advance Harley Weston lui répond.
	The x-intercepts of f(x)= 5sin (4x+pi/4)		2008-06-03
		Tom pose la question : Hi, how would I find where the x intercept in this function f(x)= 5sin (4x+pi/4)? Janice Cotcher and Harley Weston lui répond.
	Applications of trigonometry		2008-05-24
		Mohita pose la question : I have got a project in the school and i am not getting anything about the topic. The topic is that we need to find the application of trigonometry on any one of the real life situations using 3-dimensional figures. I mean how can trigonometry can be used in real life situations like navigation, architecture, survey, astronomy etc. Penny Nom lui répond.
	sinx+cos(x+30degrees)=0		2008-05-17
		geeta pose la question : sinx+cos(x+30degrees)=0 Stephen La Rocque lui répond.
	cos3A=-1/3 find cos6A		2008-05-15
		mike pose la question : cos3A=-1/3 find cos6A Penny Nom lui répond.
	sin105degree + sin15degree		2008-05-01
		meisje pose la question : sin105degree + sin15degree Can you show me the steps and how to find the exact value? Stephen La Rocque lui répond.
	sin^2(x) = -2cosx		2008-04-26
		Katelyn pose la question : I have been having some real trouble in trying to solve this equation: sin^2(x) = -2cosx Stephen La Rocque lui répond.
	Sin^2x=1/2(1-Cos2x)		2008-04-17
		Chris pose la question : Could someone please show a step by step guide on how to answer this question Sin^2x=1/2(1-Cos2x) and then explain where this identity would be useful??? Harley Weston lui répond.
	5sin^2x+3sinx=4		2008-04-17
		Chris pose la question : solve the following in the range 0 - 360 degrees? 5sin^2x+3sinx=4 Penny Nom lui répond.
	The height of a triangle		2008-04-17
		Trent pose la question : I need to know the area of a triangle. One side is 5 the base is 12 and the angle between them is 52 degrees. No height is specified. How do I find the height to get the area? Penny Nom lui répond.
	Cutting a 200 diameter pipe at 45 degree angle		2008-04-10
		Al pose la question : i want to cut a 200 diameter pipe in 45degrees. Can you demonstrate how to develop a flat rap around please Harley Weston lui répond.
	cosec [arccos (1/y)]		2008-04-09
		Tom pose la question : I am having trouble with this question. For y > 1, the value of cosec [arccos (1/y)] is? Penny Nom lui répond.
	The integral of dx / (4x^2 - 25)^3/2		2008-04-01
		Meghan pose la question : I have a question from the trigonometric substitution of my calculus course. integral of dx / (4x^2 - 25)^3/2 Harley Weston lui répond.
	2 tan theta /(1 + tan^2 theta) = sin 2theta		2008-03-25
		Charmaine pose la question : I'm having trouble on where to begin proving identities. I must prove that (2 tan theta / 1 + tan^2 theta) = sin 2theta Penny Nom lui répond.
	The length of the ramp on a motorcycle trailer		2008-03-25
		Joshua pose la question : I am currently building a motorcycle trailer. I am trying to figure out the length of the ramp so that the bikes don't scrap the trailer/ramp as they are loaded. This is the info I have: the motorcycle is 6" off the ground in the center, the point where the tires touch the ground are 80" apart, the trailer deck is 20" high. How do I figure the length of the ramp? Please show equation so I have for future reference with different measurements. Stephen La Rocque and Harley Weston lui répond.
	A hydraulic cylinder		2008-03-24
		james pose la question : I am trying to adjust the placement of a hydraulic cylinder that raises a dump bed up from the frame of a truck. How long would the cylinder (height of a triangle) have to be to raise the bed to a 70 degree angle? The base from pivot to cylinder is 132.5 inches. Stephen La Rocque lui répond.
	The limit of (sin4x)/(tan9x) as x approaches zero		2008-03-14
		stev pose la question : as x->0. How do you find the limit of f(x)=(sin4x)/(tan9X) Harley Weston lui répond.
	How tall is the tower?		2008-03-13
		chris pose la question : you are standing 120 feet from the base of a tower. the angle of the elevation to the top of the tower is 15 degrees. how tall is the actual tower? Penny Nom lui répond.
	A dog and a fire hydrant		2008-03-06
		Brittany pose la question : A bulldog is walking east along Main St. at a speed of 4 miles per hour. He wants to get to a fire hydrant on a parallel street. Initially, the bearing to the hydrant is south 62 degrees east. After 20 minutes, the bearing is south 41 degrees east. If the bulldog continues his walk, what is the closest he will be to the hydrant? Stephen La Rocque lui répond.
	cos(2x)=(cos x)^2- (sin x)^2		2008-02-25
		azarnia pose la question : comment démontrer que : cos(2x)=(cos x)²_(sin x)² Maxime Fortier Bourque lui répond.
	lim sin 4x/sin 6x as x approaches zero		2008-02-22
		josh pose la question : lim sin 4x/sin 6x x approachs 0 Stephen La Rocque and Harley Weston lui répond.
	(1-tanx) / (1+tanx) = (1-sin2x) / cos2x		2008-02-14
		isaiah pose la question : i'm having trouble proving 1-tanx / 1+tanx = 1-sin2x / cos2x, can anyone help me from going crazy? Penny Nom lui répond.
	cos t = 2 tan t		2008-02-06
		peggy pose la question : cos t = 2 tan t. Find the value of sin t. I can not solve this problem. I have the answer and some hints, but I need a step by step answer. I really want to understand how this problem is solved. Stephen La Rocque lui répond.
	Angle of Elevation		2008-01-29
		Rita pose la question : Uluru or Ayers Rock is a sacred place for Aborigines of the western desert of Australia. Chun-Wei uses a surveying device to measure the angle of elevation to the top of the rock to be 11.5 degrees. He walks half a mile closer and measures the angle of elevation to be 23.9 degrees. How high is Ayers Rock in feet? Stephen La Rocque lui répond.
	The cosine of an angle		2008-01-21
		Kristine pose la question : Find measure of unknown side cosA=0.5 Harley Weston lui répond.
	Rewrite the expression in terms of cosine to the first degree		2008-01-14
		Jamie pose la question : Hi. Im am having trouble with a problem on my math homework. I need help rewriting the expression in terms of cosine to the first degree. (sinx)^4(cosx)^2 Harley Weston lui répond.
	Two solutions using the law of sines		2008-01-14
		Kate pose la question : I am working on the Law of Sines and I have a problem that says: Find a value for b so that the triangle has 2 solutions. I am given that A = 36 degrees and a = 5. Now, I learned that for a triangle to have 2 solutions, h < a < b. BUT...my answer key says the answer is: 5 < b < 5/sin 36. I can't figure out how to make this fit with h < a < b. Harley Weston lui répond.
	cosX= -1.25		2008-01-10
		Stephanie pose la question : Why isn't there really a solution for the equation: cosX= -1.25 ? Stephen La Rocque lui répond.
	sinX=cos2X		2008-01-07
		Jennifer pose la question : sinX=cos2X how do you solve for X? I'm frustrated I've forgotten how to solve this equation. Stephen La Rocque and Harley Weston lui répond.
	How far is the jet from the lighthouse?		2008-01-07
		Natalie pose la question : Question: A ship spots a lighthouse that is 53m high, at an angle of elevation of 7 degrees that is directly north of the ship. The same ship spots a jet travelling N62E at an altitude of 1500m with an angle of elevation of 15 degrees. How far is the jet from the lighthouse? Natalie Harley Weston lui répond.
	lim sinx/(x +tanx)		2007-12-16
		shimelis pose la question : i have problem how do you solve this equation lim sinx/(x +tanx) Harley Weston lui répond.
	sin^2x=1/2(1-cos2x)		2007-12-12
		katelyne pose la question : Hello there.. I was assigned a problem that I am having trouble with in my Pre-Calc class and it is as follows: sin^2x=1/2(1-cos2x) Penny Nom lui répond.
	Solve sin(x)=x^2-x		2007-12-11
		ming pose la question : is there anyway you can solve sin(x)=x^2-x without a calculator? Stephen La Rocque lui répond.
	A triangle and a pentagon		2007-12-08
		Olivia pose la question : A regular pentagon has an area of 800 square centimetres. What is the area of the triangle extended from one side of the pentagon? Stephen La Rocque lui répond.
	Area = 1/2 ab SinC		2007-12-03
		Eileen pose la question : Given: Acute triangle ABC, with a, b, c, being the respective opposite sides to angle A, angle B, angle C, and altitude, h, drawn from angle B to b. Prove: The area of trianlge ABC=1/2abSin C Stephen La Rocque lui répond.
	If x=18, prove that sin2x=cos3x.		2007-12-02
		amy pose la question : If x=18, prove that sin2x=cos3x. find the exact values of sinx and cosx Penny Nom lui répond.
	A trig identity		2007-11-28
		Julia pose la question :     sin4x              1 - cos2x ------------    x      ----------         =     tanx 1 - cos4x               cos2x Harley Weston lui répond.
	The definition of the sine function		2007-11-22
		Indrajit pose la question : I need a explanation in this theory.......if sinθ = p/h...then sin 90 deg. = p/h or 1 = p/h or p=h .....how can a perpendicular be equal to a hypotenuse.??? Harley Weston lui répond.
	A cylindrical tank		2007-11-16
		Mario pose la question : I want to determine how many gallons i have inside a cylinder (tank) that is resting on its side (the Height), NOT standing up. I know V=pi x r2 x H. And 1 cubic foot = 7.48 gallons. Here are the dimensions r=2' H=20'. Now my question is how do I determine how much liquid i have inside, if the level of the liquid is about 1/2 of the way of its Diameter (in other words 2'). Remember this cylinder is lying on its side. Penny Nom lui répond.
	Family of functions		2007-11-12
		Russell pose la question : Consider the family of functions f(t)= Asin3t + Acos3t +Bsin8t + Bcos8t find exact values of parameters A and B so that f(0) = 2 and f ' (0) = 1 Stephen La Rocque lui répond.
	A trig identity		2007-11-10
		James pose la question : I need to prove trig identities, and I can't figure this one out 1 + sinx - cosx         1 - cosx -------------------- = ------------- 1 + sinx + cosx         sinx Chris Fisher lui répond.
	Is there a practical use for radian measure?		2007-10-26
		Paula pose la question : Is there a practical use for radian measure in any profession? Which professions might us radian as opposed to degree measure? Harley Weston lui répond.
	(3)^1/2 * tan(t/3) = 1		2007-10-26
		Rosie pose la question : Please help me with finding the solution to: (3)^1/2 * tan(t/3) = 1. Penny Nom lui répond.
	1-tan^3t/1-tant=sec^2t+tant		2007-10-23
		Brian pose la question : I need help proving: 1-tan^3t/1-tant=sec^2t+tant Harley Weston lui répond.
	lim (1- 2 cosx) / (sin(x- pi/3))		2007-10-15
		hanan pose la question : lim (1- 2 cosx) / (sin(x- л/3)) Harley Weston lui répond.
	A trig limit		2007-10-12
		Amanda pose la question : What is the limit, as x tends to zero, of: (1-cos(4x))/(xsin(x))? Thank you! ~Amanda Harley Weston lui répond.
	Irrational functions		2007-10-01
		alicia pose la question : i have a question about irrationals functions. i have been using them quite some time now, but i wonder where they can be found in daily life? i hope you can help me, Harley Weston lui répond.
	32 cis30degrees / 4 cis150degrees		2007-09-21
		Michael pose la question : Could you please help with this one. 32 cis30degrees / 4 cis150degrees Stephen La Rocque lui répond.
	A trig problem		2007-09-16
		Tracy pose la question : I have a scalene triangle ABC, angle C is 20 degrees, side AC is 8cm and side AB is 3 cm. Line CB is extended to point D which is perpendicular to point A, triangle ABD is a right-angled triangle. How do I calculate length of line AD Stephen La Rocque lui répond.
	The elevation of the sun		2007-09-10
		Elena pose la question : The "angle of elevation" of an object about you is the angle between a horizontal line of sight between you and the object. (See figure) After the sun rises, its angle of elevation increases rapidly at first, then more slowly, reaching a maximum near noontime. Then the angle decreases until sunset. The next day the phenomenon repeats itself. Assume that when the sun is up, its angle of elevation (E) varies sinusoidally with the time of day. Let t be the number of hours that has elapsed since midnight last night. Assume that the amplitude of this sinsoid is 60 degrees, and the maximum angle of elevation occurs at 12:45 p.m.. Assume that at this time of year the sinusoidal axis is at E=-5 degrees. The period is, of course, 24 hours. a. Sketch a graph of this function b. What is the real-world significance of the t - intercepts? c. What is the real world significance of the portion of the sinusoid, which is below the t-axis? d. Predict the angle of elevation at 9:27 a.m., and at 2:30 p.m. e. Predict the time of sunrise f. As you know, the maximum angle of elevation increases and decreases with the change of the seasons. Also, the times of sunrise and sunset change with the seasons. What one change could you make to your mathematical model that would allow you to use it for predicting the angle of elevation of the sun at time on any day of the year. Harley Weston lui répond.
	Where do you use trigonometry?		2007-08-21
		jenny pose la question : where do you use trigonometry besides architecture and engineering? Stephen La Rocque lui répond.
	How many complete cycles does the piston make in 30minutes?		2007-08-11
		San pose la question : A piston in a large factory engine moves up and down in a cylinder. The height, h centimetres, of the piston at t seconds is given by formula h=120sin(pi)t+200 How many complete cycles does the piston make in 30minutes? Penny Nom lui répond.
	Trig identities		2007-07-30
		Suzanne pose la question : I'm a UR University Graduate (with High honours!) but not in math: I'm taking GeoTrig, Sk Learning version, and the text is poorly written. But I was flying through the material until I hit the Trig Identities. I just don't get WHY we have them, why we should know them? What good is this "theory". All that "simplying" rarely yeilds a simple-er version! Also, give me advice for how to study them. Thanks Suzanne Harley Weston lui répond.
	Angle of depression		2007-07-23
		joyce pose la question : hello, here is my problem...... As you stand on a bridge w/c is 100 ft. above the water you are looking @ an approaching barge. If the A of top of the front of the bridge is 29.04 degrees and the angle of depression of the rear is 17.36 degrees . Find the length of the barge? Harley Weston lui répond.
	Some trig problems		2007-07-20
		Jocelyn pose la question : I wasn't able to solve this equation: only find the function using Pythagorean theorem Please help me.... sinA = 3/4 find secB tanA = 3/4 find cosA sinB = 4/5 find tan A cosA = 5 find csc A b =5; a= 12 find sin A c =25; a = 24 find cot A a = 6; c =10 find b? Find B when c = 25; a = 24 Find A when a = 5 and b = 12 csc = 1/2 find cos Penny Nom lui répond.
	Trig functions for angles not between 0 and 90 degrees		2007-07-16
		Tim pose la question : My question: Why is the value of a trigonometric function, the same, for an angle over 90 degrees and its reference angle? How are the angle and its reference related? Do they both form a triangle that has equal sides? Penny Nom lui répond.
	Another trig limit		2007-07-16
		Richter pose la question : lim (π + x)/[cos(x/2)] x-->-π Harley Weston lui répond.
	A trig limit		2007-07-16
		Richter pose la question : what is the value of lim [cos (π/x)]/(x-2) as x-->2? Harley Weston lui répond.
	Trig identities		2007-07-05
		Alex pose la question : Use the identities tan_=sin_/cos_ and/or sin*_+cos*_=1 to simplify 1-cos*_ Stephen La Rocque lui répond.
	Period of a sum of trig functions		2007-06-17
		Aakash pose la question : the period of the function f(x)=cos3x+sin4x+tan4x Stephen La Rocque lui répond.
	How high does the ladder reach?		2007-06-11
		Madi pose la question : A ladder 8 ft long resting on a house makes a 60 degree angle with the ground. how far up the house does it reach? Stephen La Rocque lui répond.
	A flagpole and a telescope		2007-06-04
		Fabiola pose la question : A telescope is mounted on a tripod 5 ft above the ground and 20 ft from a flagpole. The telescope must be rotated 48° from horizontal to see the top of the flagpole. How tall is the flagpole? Stephen La Rocque lui répond.
	Finding the hypotenuse without Pythagorus		2007-05-11
		Shelbie pose la question : How do i find the hypotenuse of a right traingle not using the pythagorean thereom if i have the measurements of the legs? Stephen La Rocque lui répond.
	Angle of Elevation		2007-05-10
		Micky pose la question : Two Buildings are on opposite sides of a street 40 feet wide. The taller of the two buildings is 580 feet tall. The angle of depression from the top of the tallest building to the shorter building across the street is 57 degrees. Find the height of the shorter building. Stephen La Rocque lui répond.
	Find the real solutions in this trig equation		2007-05-09
		tony pose la question : list all real solutions of the equation that are in the interval [0,2π) 2cos(x) + tan(x) = sec(x) Penny Nom and Stephen La Rocque lui répond.
	Evaluating sine and cosine		2007-05-06
		Selimovic pose la question : How can i solve sine or cosine for angle of, lets say 10°....Maybe it's easy but i don't know how... Penny Nom lui répond.
	A couch sliding off a truck		2007-04-30
		William pose la question : A couch with a mass of 1 X 10^2kg is placed on an adjustable ramp connected to a truck. As one end of the ramp is raised, the couch begins to move downward. If the couch slides down the ramp with an acceleration of .70 meters per second when the ramp angle is 25 degrees, what is the coefficient of kinetic friction between the ramp and couch? I drew a force diagram and if I did it correctly I identified the forces involved as "mg" (mass x gravity), "Fn" (normal force) and the "Ff" (frictional force). I know that we have the couch sliding down the ramp a .70 m/s but I don't think this a force and I'm not sure how this info fits into the problem. I know that the formula for calculating the coefficient of friction is Ff/Fn. Based upon the force diagram I drew and calculated Fn to be 1082N. I can't seem to get past this point. How do I determine what the frictional force is? Stephen La Rocque lui répond.
	Constructing an octagonal deck around a circular pool		2007-04-20
		Cliff pose la question : [I am building an] octagonal desk encompassing 17 foot diameter circle for pool. I have seen other octagonal calculations but none of these tell me how much allowance for a circle to fit within the octagon without losing the circle edge can anyone help thanks cliff Stephen La Rocque lui répond.
	y = cos(2x) and y = -0.5		2007-04-15
		kassandra pose la question : Sketch the graphs of y= cos 2x and y= -0.5 over the domain -pi < x I was wondering if someone could check it for me thanks! Penny Nom lui répond.
	Graphs of trig functions		2007-04-13
		taylor pose la question : The following graph represents a sine function in the form y=A sin B(x+C) +D or a cosine function in the form y=A cos B(x + C) +D. Write an equation of the graph in both forms Stephen La Rocque lui répond.
	sin(2x) = cos(3x)		2007-04-04
		ben pose la question : find all positive angles x such that 3x is one of the nonright angles in a right triangle and sin(2x) = cos(3x). Stephen La Rocque and Penny Nom lui répond.
	Boat trigonometry		2007-04-04
		Kimi pose la question : Hi, I have been working on the attached math problem for my college trig class for over a week. Every avenue I've tried seems to lead either to a dead end, an unreasonable answer, or extremely complicated computations. I was able to calculate the speed of the boat to 3.51 mph, but cannot figure out the measure of angle beta. Once I can figure that out, I can do the rest of the problem. Thanks, Kimi Stephen La Rocque lui répond.
	Friction of a skier		2007-03-24
		William pose la question : An olympic skier moving at 20.0 m/s down a 30 degree slope encounters a region of wet snow and slides 145m before coming to a halt. What is the coefficient of friction between the skis and the snow? Stephen La Rocque lui répond.
	The distance between two fire towers		2007-03-23
		tony pose la question : Two fire towers are 30km apart, tower A is due west of tower B. A fire is spotted from the towers, and the bearing from A and B are N76degreesE and N56degreesW, respectively. Find the distance from the fire to the straight line connecting tower A to tower B. Stephen La Rocque lui répond.
	Angles of depression		2007-03-21
		romaine pose la question : a woman of height 1.4m standing on top of a building of height 34.6m veiws a tree some distance away. she observes that the angle of depression of the bottom of the tree is 35 degrees, and the angle of depression of the top of the tree is 29 degrees. assume that the building and the tree is on level ground. (a) calculate the distance of the woman from the top of the tree measured along her line of sight. (b) determine the height of the tree. Stephen La Rocque lui répond.
	A river crossing		2007-03-16
		tara pose la question : A river has a constant current of 4 kilometers per hour. At what angle to a boat dock should a motorboat, capable of maintaining a constant speed of 20 kilometers per hour, be headed on order to reach a point directly opposite the dock? If the river is 1/2 kilometer wide, how long with it take to cross? Stephen La Rocque lui répond.
	Triple angle tangent formula		2007-03-15
		sam pose la question : Hi I am trying to derive a triple angle formulae for tan. I know i need to use compound and double angle formulae but am finding it difficult to "clean" up my fraction to get the triple angle formulae can you show me a worked derivation?! thanks Penny Nom lui répond.
	Angle of elevation		2007-03-13
		Joslyn pose la question : A ship at sea sights a 12m high lighthouse on a cliff which is 80m above sea level. If the angle of elevation to the top of the lighthouse is 27 degrees, calculate the distance from the ship to the shore. Haley Ess lui répond.
	A trig limit		2007-03-11
		Lo pose la question : tan(2*x)/sin(3*x) Penny Nom lui répond.
	sin(3a), cos(3a) and tan(3a)		2007-02-28
		mailene pose la question : hi, i...indeed,to..need..your..help how..cn..i..prove..this,formula??? sin3a=3sina-4sin^3a cos3a=4cos^3-3cosa tan3a=3tan-tan^3a /1-3tan^2a the..symbol...^is..the..expOnent Haley Ess and Penny Nom lui répond.
	Trig - Ferris wheel		2007-02-13
		Anthony pose la question : A ferris wheel is 250 feet in diameter and revolves every 40 seconds when in motion. Your step up to seat on the wheel at the bottom 2 feet above the ground so you are sitting 4 feet above the ground to start. Derive the formula for the height of your seat at time (t). If I go three times around, how long is the ride in ditance traveled? Stephen La Rocque and Penny Nom lui répond.
	tanx (cotx + tan x ) = sec^2x		2006-12-30
		Fren pose la question : tanx (cotx + tan x ) = sec^2x Penny Nom lui répond.
	A trig identity		2006-12-28
		Courteny pose la question : Prove that 1 - cos 2x + sin 2x (divided by) 1 + cos 2x + sin 2x = tan x Penny Nom lui répond.
	cos 2a+cos4a+cos6a=?		2006-12-15
		Saban pose la question : cos 2a+cos4a+cos6a=? Steve La Rocque, Chris Fisher and Penny Nom lui répond.
	A trig identity		2006-12-14
		Zamira pose la question : i need help with this proof: ((cot(x)-tan(x))/ cot(x) + tan(x)) = cos (x) Penny Nom lui répond.
	Sin 2x / 1-Cos 2x = 2 Csc 2x - Tan x		2006-12-06
		Mark pose la question : I need to prove the following: Sin 2x / 1-Cos 2x = 2 Csc 2x - Tan x Steve La Rocque lui répond.
	cos2x=1		2006-11-21
		Christina pose la question : I'm have a hard time solving cos2x=1 for exact values between 0<_x <360 Stephen La Rocque and Penny Nom lui répond.
	tan1/2x + cot1/2x = 2cscx		2006-11-04
		Jazmin pose la question : Prove tan1/2x + cot1/2x = 2cscx Penny Nom lui répond.
	Finding the legth of a guy wire		2006-10-15
		Aubrey pose la question : a radio tower 500 feet high is located on the side of a hill with an inclination to the horizontal of 5 degrees. how long should two guy wires be if they are to connect to the top of the tower and be secured at two points 100 feet directly above and directly below the base of the tower? Stephen La Rocque lui répond.
	How high (in feet) is the mountain?		2006-08-29
		Briana pose la question : A survey team is trying to estimate the height of a mountain above a level plain. From one point on the plain, they observe that the angle of elevation to the top of the mountain is 29 degrees. From a point 2000 feet closer to the mountain along the plain, they find that the angle of elevation is 31 degrees. How high (in feet) is the mountain? Stephen La Rocque lui répond.
	The development of trigonometry		2006-08-15
		Eugene pose la question : Can you please give the exact time line of trigonometry. Penny Nom lui répond.
	A perpendicular intersection of two barrel vaults		2006-07-21
		Neal pose la question : I'm wanting to build a series of architectural models of different roman and medieval buildings out of cardboard. Once I have perfected the models I want to print them out on card stock so that school kids (or anyone else) can make the buildings. A feature of many of these models is the cross or groin vault (a perpendicular intersection of two barrel vaults). A single barrel vault is easy to imagine as a plane (a rectangular piece of cardboard) that will be folded into a semi-circular arch. The intersection of a second barrel vault and this one is presenting me with problems. The second plane needs to have an ellipse cut into it so that when it is folded into the arch, it will mate up with the curve of the first barrel vault. Given that the two pieces of card have identical widths (and therefore identical arcs in cross section) is there a way to calculate the ellipse that needs to be cut so that it can be cut before the second arch is folded? Edward Doolittle lui répond.
	Calculating the belt length of a three pulley system		2006-07-16
		Mark pose la question : I have a 3 pulley system with sides abc and pulleys ABC. Pulley A has radius of 10cm, pulley B has radius of 20cm, and pulley C has radius of 3cm. The side lengths are: (center to center of pulleys) between pulleys AB = 75cm, between pulleys BC = 100cm, and between pulleys AC = 50cm. I set these side lengths up as (according to law of sines and cosines) a = 100cm, b = 50cm, and c = 75cm. What is the length of the belt required for this system? I need to know how I would set this problem up and solve. Stephen La Rocque lui répond.
	A problem with arc sine		2006-07-07
		Scott pose la question : How to prove arc sin x = arc tan( (x)/√(1-x2)) Penny Nom lui répond.
	A trig problem		2006-06-24
		Greg pose la question : A and B are two towers, B being 4 km due east of A. The true bearings of a flagpole, C, from A and B are α east of north and α west of north respectively. The true bearings of a second flagpole, D, from A and B are (α + β) east of north and (α - β) west of north respectively. Assuming A, B, C, and D are on level ground, and that α = 25, β = 10, find the distance between C and D. Penny Nom lui répond.
	The area of a sector and a triangle		2006-06-23
		Howard pose la question : I thought of the following problem which is similar but much simpler than the tethered goat problem: What is the angle(it is more illustrative in degrees)of arc of a unit circle so that the area between the chord it subtends and the arc length is equal to the area of the triangle with opposite side the subtended chord. Stephen La Rocque and Penny Nom lui répond.
	find the height of the tower		2006-06-17
		Evelyn pose la question : The angle of elevation from a point 89.6' from the base of a tower to the top of the tower is 42'40'... find the height of the tower Penny Nom lui répond.
	What is the value of csc (-2pi/3)?		2006-06-04
		Kishor pose la question : What is the value of csc (-2pi/3)? Stephen La Rocque lui répond.
	A trig identity		2006-06-04
		Courtney pose la question : Show that this equation is an identity: (sin x + sin 2X)/(cos x - cos 2x) = cot(x/2) Stephen La Rocque lui répond.
	A limit involving trigonometry		2006-05-02
		Allie pose la question : My question is how do you solve. lim as t goes to 0 [sin squared *3t] / t squared? Penny Nom lui répond.
	Finding the side of a triangle		2006-04-06
		Carole pose la question : okays, well, im having difficulty finding the side of a triangle. It is a right triangle and the information given is that the hypotonous is 24 and the angle adjacent to the 90 degree is 32. Im trying to find X, which is placed on the bottom leg of the triangle, and have no idea how to do it. can you explain to me how to get the answer, please? i'd like to know for future reference, please. thank you. Stephen La Rocque lui répond.
	Two trig questions		2006-04-04
		mandy pose la question : I have a few questions that I need help with for my precal class in college. The following have to prove the trigonometric identities: cos4x + 2cos2x sin2x + sin4x = 1 sin4x - cos4x = 1 - 2cos2x thanks you, Stephen La Rocque lui répond.
	cos(3X)		2006-03-29
		Joshua pose la question : I'm having trouble proving that cos(3X)=cos3X -(cosX)(sin2 X) Penny Nom lui répond.
	A trig identity		2006-03-28
		Iqbal pose la question : Could you please prove, [tan(x)-sin(x)]/sin3(x)=sec(x)/[1+cos(x)] Stephen La Rocque lui répond.
	Solve the equation cos x = sin 20 where x is acute.		2006-03-26
		Elle pose la question : Solve the equation cos x = sin 20 where x is acute. Stephen La Rocque lui répond.
	The waterway between Lake Huron and Lake Superior		2006-03-21
		Trenae pose la question : the waterway between lake huron and lake superior separates the u.s and canada.it is usually 13 feet above the water when its closed and each section is 210 feet long if the angle of elevation is 70 degrees then what is the distance from the top of the drawbridge to the water and the width of the gap created by the 2 sections of the bridge Penny Nom lui répond.
	Find the ground speed and the planes true heading.		2006-02-05
		Jimmie pose la question : An aircraft going from city A to city B on a bearing of S69E (degrees) is traveling at a speed of 430 mph. The wind is blowing out of the north to south at a speed of 25 mph. Find the ground speed and the planes true heading. Penny Nom lui répond.
	A trigonometric identity		2006-01-22
		Sarfaraz pose la question : Prove the following trigonometric identity. sin2x = tan2x/(1+tan2x) Penny Nom lui répond.
	The height of a right triangle		2005-12-21
		Sanmantha pose la question : I am trying to solve for the height of a right triangle. The base is .05 mm, and the apex is 0.5 degrees. I vaguely recall from high school that this should be enough information to solve for height, but I can't remember what equation(s) to use. Penny Nom lui répond.
	A regular octagon is inscribed in a circle		2005-12-13
		Carlin pose la question : A regular octagon is inscribed in a circle of radius 15.8 cm. What is the perimeter of the octagon? Penny Nom lui répond.
	A pair of trig equations		2005-12-05
		Kevin pose la question : I am trying to solve for A and B but haven't been able to find a trig identity that will help me. 1.414 = .5cosA + cosB .5 = .5sinA - sinB how do I solve this? Penny Nom lui répond.
	How is trigonometry applied to everyday life?		2005-12-03
		Yadira pose la question : My question is how is trigonometry applied to everyday lives and functions. Ex: Builders use it but how and what are some examples of the trig-functions or formulas that they use? Harley Weston lui répond.
	The elevation of the top of the house		2005-11-13
		Chloe pose la question : Karen is standing 23 metres away from the base of a 23 metre high house. Assume that Karen's eyes are 1.5 metres above ground. Find the elevation of the top of the house from Karen's eye line. Penny Nom lui répond.
	The height of a tower		2005-11-08
		Vinita pose la question : Observers at point A and B, who Stand on level ground on opposite sides of a tower, measure the angle of elevation to the top of the tower to be 33 degrees and 49 degrees respectively. Another point C is 120 m from point B, Triangle ABC =67 degrees and BAC = 31 degrees. Find the height of the tower to the nearest metre. Penny Nom lui répond.
	The length of a chord		2005-11-03
		Sue pose la question : How do you determine the length of a chord when given the diameter of the circle (1.6m) and that the angle = 7π/8 Penny Nom lui répond.
	sin(kx) = x		2005-10-20
		David pose la question : What is an integer value for k so that sin(kx) = x has exactly 2005 solutions? How does one arrive at the answer? Harley Weston lui répond.
	Determine the height		2005-10-14
		Paul pose la question : if you know the distance to the base and the angle to the top how can you determine the height Penny Nom lui répond.
	Elliptic trigonometry		2005-09-15
		Krystal pose la question : I'm currently searching for a science project topic and i have the idea of deriving elliptic trigonometry analogous to circular trigonometry. My questions are: Is this project "possible" to do? Chris Fisher and Harley Weston lui répond.
	The length of a chord		2005-09-08
		A student pose la question : how do you find the length of a chord given the angle and radius of the circle Penny Nom lui répond.
	cos x * cos 2x * cos 4x * cos 8x		2005-08-29
		Leandro pose la question : A = cos x * cos 2x * cos 4x * cos 8x What's the value of log A at base 2? Chris Fisher and Penny Nom lui répond.
	A television antenna sits on a roof.		2005-07-30
		Liz pose la question : A television antenna sits on a roof. Two 76-foot guy wires are positioned on opposite sides of the antenna. The angle of elevation each makes with the ground is 24 degrees. How far apart are the ends of the two guys wires? Penny Nom lui répond.
	The value of n*tan*(180/n) tends to pi		2005-07-11
		Daniel pose la question : I am 14 and i have been given a piece of maths coursework whereby a farmer has to fence off a piece of land as large as possible using 1000m of fence. I already know that the formula for working out the area of any shape of a 1000m perimeter = 5002/ n*tan*(180/n), however, after some research I have found out that as the number of sides (n), tends to infinity, the n*tan*(180/n) tends to pi. Why is this? Penny Nom lui répond.
	arccos(5/13)		2005-05-31
		Kyle pose la question : I would like to know how to evaluate the problem of: Arccos 5/13. Penny Nom lui répond.
	sin x + sin 2x + sin 3x + sin 4x = 0		2005-05-10
		Elia pose la question : I tried many times, but can't get to solve the following question: sin x + sin 2x + sin 3x + sin 4x = 0 Chris Fisher lui répond.
	cos(2x) = sin(3x)		2005-04-14
		A student pose la question : Show that if x= 18 degrees, then cos2x =sin 3x. HENCE find the exact value of sin 18 degrees, and prove that cos 36 - sin 18 =1/2. Andrei Volodin, Claude Tardif and Penny Nom lui répond.
	tan55.tan65.tan75=tan85		2005-03-30
		Jesus pose la question : My name is Jesus and I´m a secondary student. I´m trying to verify a trigonometric identity but I don´t know how to do it.please help me!!!!!!!!!. The identity is : tan55º.tan65º.tan75º=tan85º (the sign (.) indicates multiplication) Chris Fisher and Penny Nom lui répond.
	A wishing well		2005-03-28
		Don pose la question : I am building a wishing-well out of pieces of 2-by-4. I have included a picture of a miniature version of what I want. There are to be ten 2-by-4 pieces around the well and I want the circle around the outside of the structure to have a diameter of approximately 3 feet. How long to I cut the 2-by-4's to build the wishing-well. Thanks, Don Harley Weston lui répond.
	Find the height of the pole		2005-03-22
		Dorothy Jean pose la question : From the top of a building 70ft.high, the angle of elevation of the top of the pole is 11.2 degrees. From the bottom of the building the angle of elevation of the top of the pole is 33.4 degrees. Find the (a) height of the pole and (b) the distance from the building. Penny Nom lui répond.
	A trig identity		2005-03-06
		Patrick pose la question : im trying to verify this identity: sin(x)+sin(5x) -------------------- = tan(3x) cos(x)+cos(5x) Chris Fisher lui répond.
	cos 2x = sin x		2005-01-22
		Kris pose la question : solve the equation cos 2x = sin x for 0<= x < 360 Penny Nom lui répond.
	Finding the missing side of a triangle		2005-01-20
		Jason pose la question : I found a geometry problem that reads as follows:In triangle ABC, Penny Nom lui répond.
	The angle between two forces		2005-01-19
		Abraham pose la question : One force of 20 pounds and one force of 15 pounds act on a body at the same point so that the resultant force is 19 pounds. Find, to the nearest degree, the angle between the two original forces. Penny Nom lui répond.
	The tide at a boat dock		2005-01-11
		Abraham pose la question : The tide at a boat dock can be modeled by the equation y = -2cos(pi/6 t) + 8, where t is the number of hours past noon and y is the height of the tide, in feet. For how many hours between t=0 and t=12 is the tide at least 7 feet? Penny Nom lui répond.
	Modelling monthly temperature with a cosine		2004-12-25
		Regis pose la question : The average monthly temperature for a location in Ontario as a function of month number can be modelled using the equation y = a cos[k(t + b)] + d. Harley Weston lui répond.
	sin(3A)		2004-10-20
		A student pose la question : Express sin3A in terms of sinA and cosA. Penny Nom lui répond.
	X is due north of Y ...		2004-08-11
		A student pose la question : X is due north of Y and 2km distant. Z is due east of Y and has a bearing of S35°12'E from X. How far, to the nearest metre, is Z from X? Penny Nom lui répond.
	Two trig problems		2004-08-04
		Tracie pose la question : sin^2x - sin x -12 = 0 sin 2x = -sin x Penny Nom lui répond.
	A trig problem		2004-08-02
		A student pose la question : Given that the maximum value of [sin(3y-2)]^2 -[cos(3y-2)]^2 is k. If y>7, Find the minimum value of y for which [Sin(3y-2)]^2 - [cos(3y-2)]^2 =k. Penny Nom lui répond.
	The height of a building		2004-06-16
		Lauren pose la question : I have a homework assignment to measure a building on my school's campus. I have to stand at least 40 ft away from the building and find the angle of elevation from my feet to the top of the building. Then I have to walk at least 40 ft form that point, record the distance as X, and find the angle of elevation from my feet to the top of the building. Using X and the angles, I have to determine the height of the building. I used a protractor and a weighted string to find the angle of elevation from my eyes to the top of the building. But I haven't been able to find the way to measure the angle of elevation from my feet to the top. Penny Nom lui répond.
	Programming without trig functions		2004-05-25
		Derek pose la question : I am a programmer trying to calculate the following. What is the formula to find the cross-sectional area of a cylinder with out using any trig functions? or better yet, how can you calculate any given volume in a cylindrical tank with spherical heads with out trig functions? I am using a PLC (programmable logic controller) to do this and trig functions are not available. Harley Weston lui répond.
	Some trig expressions		2004-05-23
		A student pose la question : Prove: sin A + sin B = 2sin(A+B/2)cos(A-B/2) cos A - cos B = -2sin(A+B/2)sin(A-B/2) cos A + cos B = 2cos(A+B/2)cos(A-B/2) sin A - sin B = 2cos(A+B/2)sin(A+B/2) Penny Nom lui répond.
	An oil-drilling platform		2004-04-27
		Alie pose la question : An oil-drilling platform is located in the Gulf of Mexico 3.25 miles from the nearest point on shore. From a point B on the shore due east of A the bearing of the platform is S51.2W. How far is it from B to the platform? Penny Nom lui répond.
	The height of a building		2004-03-31
		Nat pose la question : Two buildings are 26.3m apart. From the top of the shorter building the angle of elevation to the top of the taller building is 35.9 degrees and the angle of depression to the base of the taller building is 54.7 degrees. What is the height of the taller building? Penny Nom lui répond.
	Cosine of 35 degrees		2004-03-03
		Jason pose la question : How do you find the exact solution to cosine 35 degrees. Chris Fisher lui répond.
	Proof by induction		2004-03-02
		Chris pose la question : I need some help of how to solve the problem "use the principle of mathematical induction to prove that the following are true for all positive integers" cos(n x pi + X) = (-1)^n cosX any help would be appreciated Penny Nom lui répond.
	Sin(3x), cos(3x) and tan(3x)		2004-01-28
		Jon pose la question : What is the identity for cos3x, sin3x, and tan3x? In class, we learned double angel identities and were asked to find out the identity to these three trig functions. If you can help, please do. Also, i know that the cos4x- sin4x is the same as cos2x. Is cos8x-sin8x = cos2x also true? Thank you.s Chris Fisher lui répond.
	Some trig problems		2004-01-18
		Weisu pose la question : I have some questions about pre-calculus. (1) (2(cos(x))^2)+3sin(x)-1=0 (2) sin(x)cos(x)=(1/2) (3) 3sin(x)=1+cos(2x) (4) tan(x)*csc(x)=csc(x)+1 (5) sin(arccsc(8/5)) (6) tan(arcsin(24/25)) (7) arccos(cos(11pi/6)) the last problem uses radian measure. Penny Nom lui répond.
	Finding angles		2003-12-02
		Jason pose la question : I AM TRYING TO SOLVE A TRIG PROBLEM AND HAVE FORGOT HOW TO DO IT. WHAT I HAVE IS A RIGHT TRIANGLE WITH SIDE A BEING 14 FEET AND SIDE B BEING 3 FEET, USING PYTHAGOREAMS THEOREM SIDE C SHOULD EQUAL 14.318 FEET ON A RIGHT TRIANGLE BUT I AM TRYING TO REMEMBER HOW TO FIND MY ANGLES OTHER THAN THE ONE THAT IS 90 DEGREES. Penny Nom lui répond.
	Laws of sines and cosines		2003-11-23
		A parent pose la question : On the one side of a stream lines PA= 586.3 feet, PB = 751.6 feet are measures, angle APB being 167 degrees and 36 min. Q is a point on the opposite side of the stream. Angle PAQ=63 degress and 18 min and PBQ=49 degrees and 24 min. Find PQ. Penny Nom lui répond.
	A trig identity		2003-11-12
		A student pose la question : I can't prove this identity. Can you please help me? (1-tanx)/(1+tanx)=(1-sin2x)/(cos2x) Penny Nom lui répond.
	Two precalculus problems		2003-08-04
		Kate pose la question : Please help me verify the identity: cos2x(sec2x-1)=sin2x Also I am having trouble withdetermining whether f(x) is odd, even, or neither f(x)=x3-x Penny Nom lui répond.
	Odd powers of sine and cosine		2003-06-25
		Antonio pose la question : Can you please tell me how to integrate a trig function involving sine and cosine? I know if the powers of both the sine and cosine are even and nonnegative, then I can make repeated use of the power-reducing formulas. But for the question I have on my hand, the powers of both sine and cosine are odd: ( sin3x + cos7x ) dx. Harley Weston lui répond.
	Two trig problems		2003-06-10
		Bett pose la question : I have this ongoing trouble with trig and solving triangles with laws of cosines and sines!! For example if it asks to solve triangle FGH, given angle G=102.7 , side f=14.2, and h=18.6. Now do I use law of cosines because I don't have the measure of an angle and length of the opposite side??I don't know where to go from here,I am totally confused!!! I also have a problem with this word problem I have been doing. It asks: An airplane flies 847.5 km at a bearing of 237.3 degrees. How far south and west fo its original position is it? Huh? Please help! Penny Nom lui répond.
	A trig identity		2003-05-20
		Patty pose la question : Please help with the following 1/ tanx + cotx = sinxcosx Penny Nom lui répond.
	sin theta = 7/8		2003-05-07
		Patty pose la question : If sin0 = 7/8 and 0 is in quadrant 2, find the other five trigonometric functions of 0. (report your answers in radical form) Penny Nom lui répond.
	Write sin(3x) in terms of sin(x)		2003-05-05
		A student pose la question : Write sin 2x in terms of sin x Penny Nom lui répond.
	Three proffs of a trig identity		2003-03-18
		Nadene pose la question : Prove the identity. cos [x + (y-pi/2)] = sin (x+y) A hint was also provided which is: "Apply cos (alpha + beta) first then within that apply cose (alpha-beta)" Penny Nom lui répond.
	A trig identity		2003-02-22
		Ron pose la question : We have spent hours trying to solve the following identity without success. Can you give us some hints as to how it is done? 1 + tan(x) tan(2x) = tan(2x) cot(x) -1 Penny Nom lui répond.
	Radians		2003-01-16
		Erikson pose la question : I am a student in the 10th grade and attending advanced math at my high school. I was assign to do a report about the unit circle and the radian. But there seems to be no information available about the history of the radian; who first found out about them, which civilizations used it if any. Well, hopefully you'll assist me in this troubling question. Thank you for your kind consideration. Penny Nom lui répond.
	y = 1 - sin(x + 60)		2002-12-10
		Eman pose la question : Sketch the graph of y = 1 - sin(x+60). for 0 <= x<= 360, giving the coordinates of the maximum and minimum points and the pints where the curves crosses the y axis. Penny Nom lui répond.
	Trigonometry		2002-12-01
		Lance pose la question : My question is: FIND ALL SOLUTIONS cosx=1-sin(x/2) if x[0,2pi) ALSO: Given cscx=-5/4 and cot>0, find csc(x/2) and cot(x/2) Penny Nom lui répond.
	Trigonometry problems		2002-12-01
		Chiara pose la question : Find tan 35pi/4 Graph y = cos2x - 2sinx Penny Nom lui répond.
	An identity?		2002-10-27
		Jenna pose la question : I can't prove 1-sinQ 1 ---- = tanQ + --- 1+sinQ cosQ Penny Nom lui répond.
	An identity in trigonometry		2002-10-17
		Alex pose la question : I really need help with proving this identity. (1+cosx+sinx)/(1+cosx-sinx) = secx + tanx Penny Nom lui répond.
	A Circle is evenly divided into six equal triangles		2002-09-16
		Marilynn pose la question : A Circle is evenly divided into six equal triangles leaving an area between the outside of the circle and the one side of the triangle. This area is measured as 3.14. What is the length of the radius, one line on the triangle? Paul Betts lui répond.
	The tangent to a curve and the tangent of an angle		2002-08-26
		A teacher pose la question : Is there a relationship between the tangent of a curve(line touching the curve at one point) and tangent (the trigonometric function)? Chris Fisher lui répond.
	How far apart are the transmitters?		2002-05-18
		Jeff pose la question : A ship at sea is 70 miles from one transmitter and 130 miles from another. The measurement of the angle between the signals is 130 degrees. How far apart are the transmitters? Penny Nom lui répond.
	The law of cosines and obtuse angles		2002-05-09
		Bryant pose la question : The question that I am pondering is that I need to derive the law of cosines for a case in which angle C is an obtuse angle. Penny Nom lui répond.
	An identity(?)		2002-05-02
		A student pose la question : prove identity sin 2x/1-sinx= secx+1/secx Paul Betts lui répond.
	A triangle in a circle of radius 6		2002-03-26
		Marko pose la question : In a circle of radius 6, a triangle PQR is drawn having QR = 8 and PQ = 10. Determine the length of PR Chris Fisher lui répond.
	A trigonometric identity		2002-03-22
		Debby pose la question : I am stuck on a problem and wondering if you can help?? It is: Prove the following: sec2(X)+csc2(X) = sec2(X)csc2(X) Harley Weston lui répond.
	sin 2x = cos 3x		2002-02-25
		Allan pose la question : solve: sin 2x = cos 3x Primary question: how do you handle the cos 3x? Paul Betts and Chris Fisher lui répond.
	The size of a lot		2002-01-26
		Claudia pose la question : I own a piece of property that I need to know the square feet for assessment purposes. The figure they came up with is wrong. They measured from one point to another and halved the sums but that means I own the cul de sac and we don't. My lot is 55 feet wide and one side is 108.96 feet and the other side is 146.04 that extends all the way to a circle. The front of the lot on the cul de sac is stated on the survey like this. 78.21 feet where R=40 feet. This large arc is taken off the size of our land. How many square feet is our lot. Harley Weston lui répond.
	Some trig problems		2002-01-22
		Grant pose la question : Solve each problem for theta(there is no sign on my computer)for 0 is less than or equal to theta which is less less than 360 2cosx-1=0 cosx=1/2 Anwser 60,300 tanx-2sinxtanx=0 tanx(-2sin+1)=0 (factor ?) tanx=0 and sin= 1/2 (solve from there?) 2sinx-cscx=0 2sinx-1/sinx=0 3sinx-1=0 3sinx=1/3(?) 4cos(2x)+2cosx= -1 8cosx+2cosx+1=0 10cosx+1=0 10cosx= -1/10 (?) cos(2x-30)=1/2 cos2x-cos30=1/2 cos2x-cos30-1/2=0 i don`t know what to do know Sinx+cosx=0 Square both sides? Claude Tardif lui répond.
	The tangent function		2002-01-12
		Justine pose la question : if you know that sin45degress = cos45degrees, how do you know that tan45degrees = 1? Penny Nom lui répond.
	An octagon inscribed in a circle		2002-01-10
		Kent pose la question : A circle of 30 in. diameter has an octagon (8 equal chords) inscribed in it. What is the length of each chord? Chris Fisher lui répond.
	A 3 dimensional 5 pointed star		2001-11-08
		Kent pose la question : I am looking for a formula that will give me a layout for a 3 dimensional 5 pointed star. I want to form it out of sheet metal, using 5 polygons and soldering them at the apex. Can you please help me with this? I would like to be able to give the formula the height of the star from the bottom two points to the top point and also how deep the star is. Thank you very much! Judi McDonald lui répond.
	3pi/2 - pi		2001-10-29
		Karen pose la question : I need to simplify this a) 3pi/2 - pi Penny Nom lui répond.
	eix = cosx + isinx		2001-10-10
		Peter pose la question : Given: eix = cosx + isinx substitute -x for x to find e-ix, simplifying your answer use the given and part a to find an identity for cosx making no reference to trig functions find an identity for sinx . . Penny Nom lui répond.
	Solving trig equations		2001-09-22
		Asad pose la question : Can you please explain to me how to solve trig Equations,e.g sin(x)=x4+12/2+cos(x)=x6+9/3= (if this can be solved) Claude Tardif lui répond.
	Standard angles		2001-08-05
		Nagaraj pose la question : Why 0o , 30o , 45o , 60o ,and 90o are taken as standard angles in Trigonometry? Why can't we take some other angles as standard angles? Chris Fisher lui répond.
	The radius of a planet		2001-07-30
		Jessica pose la question : A satellite is orbiting the earth at an altitude of 100 miles. If the angle of depression from the satellite to the horizon is 50 degrees, what is the radius (to the nearest mile) of the planet? Harley Weston lui répond.
	A trig identity		2001-07-27
		Jeff pose la question : prove this identity and show steps tan(x/2+pi/4)=secx+tanx Harley Weston lui répond.
	Radian measure		2001-07-26
		Amy pose la question : i have to find out what is meant by the radian measure of an angle and compare it to the measure of an angle in degrees. Harley Weston lui répond.
	Three chords		2001-06-28
		Paul pose la question : AE is a diameter of a circle and AC, CD and DE are chords of lengths 1, 2 and 3 respectively. (See the diagram.) Find the ridius of the circle. Harley Weston lui répond.
	The angles in a triangle		2001-05-11
		Nikki pose la question : Find the measure, to the nearest degree, of each angle of a triangle with sides of the given lengths. 26, 35, 40 Penny Nom lui répond.
	The unit circle and trigonometry		2001-04-05
		Ashley pose la question : "My teacher wants us to find out what a unit circle is, which I found out, a circle with the radius of 1, but the problem is he wants us to show the relationship between the unit circle and the sine(30,45,60 degrees), cosine(30,45,60 degrees),and tangent ratios(30,45,60 degrees). I need help with this and my teacher will not help us out. Thanks very much ... Penny Nom lui répond.
	A famous landmark		2001-03-23
		Corinne pose la question : A family is traveling due west on a road that passes a famous landmark. At a given time the bearing to the landmark is N 62 degrees W, and after the family travels 5 miles farther the bearing is N 38 degrees W. What is the closest the family will come to the landmark while on the road? Harley Weston lui répond.
	The angle of elevation		2001-03-08
		Jeffrey pose la question : At a Certain time, a vertical pole 3m tall cast a 4m shadow. What is the angle of elevation of the sun? Harley Weston lui répond.
	cot(arcsin 3/5)		2001-01-07
		Jason pose la question : Find value. Assume that all angles are in Quadrant 1. cot(arcsin 3/5) Harley Weston lui répond.
	Triangles and trigonometry		2000-11-30
		Mose pose la question : If I have a right triangle, and I know the lengths of all three sides, is there a formula that will allow me to determine the measurements of the 2 non right angles? Harley Weston lui répond.
	Trig identity crisis		2000-11-29
		Rhiannon pose la question : I have tried many times to find the answer to these problems but I can't I am in grade 12 tan(x)=csc2(x)-cot2(x) cos(x)/csc(x)-2sin(x)=tan(x)/1-tan(x) cos(x)[ tan2(x)1-1]/cos2(x)+sin2(x)=sec(x) Harley Weston lui répond.
	Overlapping a circle and a square		2000-10-28
		Jacky pose la question : A square with a dimension 20 by 20cm. and a quarter of the circle with the radius of 25cm (A quater of a circle is created by 2 cuts that are perpendicular bisectors of each other where the intersecting point is at the centre of the circle). With these 2 pieces, the 2 pieces are placed over each other in which the 90o angle of the quarter circle matches with one of the right angles on the square. Now, calculate the overlapping area of the 2 figures. Chris Fisher and Harley Weston lui répond.
	Logs and trig functions		2000-09-12
		Becky pose la question : How do they get these answers? log 8 + log 2 = ? Answer is: log 16 For 0 degree < x < 90 degree, how many solutions are there for the equation 2sin x = cos x? Answer: 1 Penny Nom lui répond.
	Trigonometry		2000-09-02
		david pose la question : determine the sum of the angles A,B where 0 <= A , B <= 180 (degrees) sinA + sinB = sqr(3/2) , cosA + cosB = sqr(1/2) Chris Fisher lui répond.
	Some trigonometry		2000-08-11
		Angela pose la question : I have some PreCal questions. I am a student at the secondary level. I would be very grateful for your help. Solve the equation for theta (0 <= theta < 2pi). tan2(theta) = 3 I know sec2(theta) -1 = tan2(theta) . . . Harley Weston lui répond.
	A semi-circle and a triangle		2000-07-28
		Ben pose la question : A semi-circle and an isosceles triangle ABC have the same base AB and the same area. The equal angles in the triangle are BAC and CAB. I have to find the value of each of these angles. Harley Weston lui répond.
	A trig question		2000-07-01
		Will pose la question : An open rectangular tank a units deep and b units wide holds water and is tilted so that the base BC makes an angle theta with the horizontal. When BC is returned to the horizontal, who that the depth of the water is (a squared) * cot theta div 2b units Harley Weston lui répond.
	Two problems		2000-06-12
		Sharon pose la question : If f(4)=0 and f(6)=6, which of the following could represent f (x)? A. 2/3x-4 B. x+2 C. x-4 D. 3/2x+6 E. 3x-12 these are problems to study for a test so I need to know the answer and how it was solved! I have one more question If 180o < theta < 270o and tan theta = 4/3, then sin theta =? A. 5/4 B. -4/5 C. 3/5 D. 12/5 E. -3/5 Harley Weston lui répond.
	Projecting a line segment onto a plane		2000-06-08
		Monica pose la question : What is the measure of the angle determined by a 14 inch segment and its projection into a plane if the length,in inches, of the projection into the plane is 7 inches? Penny Nom lui répond.
	Using the inverse sine function		2000-05-31
		Nelson Rothermel pose la question : This has me completely baffled. I have to use the laws of sine or cosine to find the angles of a triangle when I have 3 sides, so I can't go 180-x-y when I have 2 angles. Now, I have a triangle with values of 3, 7, and 9. Here are the steps I used (A,B,C are angles; a,b,c are opposite sides): angle A (16.1951 degrees): cos-1*((b2+c2-a2)/(2*b*c)) angle B (40.6011 degrees): sin-1*(b*sin(A)/a) angle C (56.7962 degrees): sin-1*(c*sin(A)/a) If you notice, A+B+C does not equal 180. According to the book, A and B are correct, but C is supposed to be 123.2038 degrees. Why doesn't it work??? Harley Weston lui répond.
	A trigonmetric identity		2000-05-15
		Caitlin pose la question : My name is Caitlin and my question is from 11th grade math and I'm a student my question is I need to solve this identity : cos x csc x - sin x sec x = 2 cot 2x Paul Betts lui répond.
	Solve 2sin 3x-1=0		2000-05-11
		Cynthia pose la question : How would you solve 2sin 3x-1=0? I don't know what to do with the 3. Penny Nom lui répond.
	Trig functions		2000-05-09
		Melissa pose la question : Find all solutions in the interval (0,2pi) 2cos2x-3cosx-4=0 Paul Betts and Harley Weston lui répond.
	sin(7pi/12)		2000-05-04
		Kristel pose la question : What is the exact value of sin 7pi/12? Chris Fisher and Paul Betts lui répond.
	A trogonometry problem		2000-03-12
		A student pose la question : Find all values of X in the interval 0 degrees <= x < 360 degrees that satisfy the equation 2sin x - cos 2x = 0. Harley Weston lui répond.
	Folding a page		2000-03-01
		Krista Bischoff pose la question : One corner of a page of width a is folded over and just reaches the opposite side. Express L, the length of the crease, in terms of x and a. I can't get the picture to copy to this form so I guess I will have to try and describe the picture the best that I can. The top right hand corner is folded to the left side, almost half way down. The width of the paper is a ( the width of the bottom part which is not folded.) The creased side is L and the part shorter part of the folded area is x (the part that would have been the top right of the original piece.) Chris Fisher lui répond.
	Triple angle formula		2000-02-23
		Sara pose la question : Can one derive a triple angle formula for sine and cosine? If so, how? Chris Fisher lui répond.
	A trig identiry		2000-02-23
		Ashlee pose la question : I am having problems doing this problem. Can you help? Verify the identity: (1+cot2X)(1-cos2X)=2 Harley Weston lui répond.
	A trig identity		2000-02-17
		Eric pose la question : Question: How do I solve this problem? sin3x cos3x _____ - _____ = 2 sinx cosx Chris Fisher lui répond.
	Period		1999-12-28
		Mahdawi pose la question : I have attached a diagram of the graph, and I need to find out its period. I really don't understand how to do so, please help! Harley Weston lui répond.
	Proving a trigonometric identitiy		1999-12-17
		Ryan pose la question : I need to figure out how to prove that sec2x + csc2x = sec2x csc2x. I am not sure where to start out with it and whether I should use reciprocal, quotient, or pythagorean. Penny Nom lui répond.
	Sines & cosine laws		1999-12-10
		Pierre Boivin pose la question : Triangle LMN, angle L=71 degree , LM= 7.2 , MN=8.3 , ln= 5.9 The questiion was to find angle M. Using the cosine law I found the answer to be 44 degree. It is also the book answer. Using the sines law I found the answer to be 42.2 degree. why can't I use the sines law. Chris Fisher lui répond.
	Cos x = -1/2		1999-12-01
		Pierre Boivin pose la question : When I factor[ 2cos (square) - 5cos -3], I get (2cos + 1)(cos - 3). 2cos + 1 = 0, 2cos = -1, cos = -0.5,. Using inv cos on calculator, I get 120 degree related angle. When I graph I get two values, between 90 and 180 degree and between 180 and 270 degrees. How do I find those two values. How do use 120 degree in relation with the x axis. Penny Nom lui répond.
	Women in Trig		1999-10-11
		Sandra Mills pose la question : I am looking for some information about women who have contributed to the discipline of trigonometry. In addition to this I have been asked to choose a subject pertaining to Roman times for my Roman and American Lit class. I wanted to do a project and presentation related to mathematics, but could use some suggestions-- maybe how mathematics were applied as in engineering and the structure of the Roman buildings. Could you please provide some information about the history of mathematics and it's applications in Roman times. I am also open to any other suggestions for topics. Chris Fisher lui répond.
	sin x = x/10		1999-10-07
		Amandeep Grover pose la question : Solve the equation sin x = x/10 Harley Weston lui répond.
	A trig limit		1999-10-06
		Yannick Gigandet pose la question : What is the limit, as x approaches pi/3, of (1-2cosx) / sin(x-(pi/3)) ? Penny Nom lui répond.
	Two limits		1999-10-02
		Jennifer pose la question : How do I find lim (1-cosx)/(x^2) as x-> 0 and lim (tan3x)/x as x->0 Harley Weston lui répond.
	Trigonometry history		1999-09-25
		Nikki pose la question : What is trigonmetry ? Who invented it ? What is it's purpose ? And anything else that you can tell me that is related to Trigometry. Chris Fisher lui répond.
	Distance between the windows		1999-09-19
		Lawrence pose la question : An observer on level ground is at distance d from a building. The angles of elevation to the bottom of the windows on the second and third floors are a and b respectively. Find the distance h between the bottoms of the windows in terms of a b and d Harley Weston lui répond.
	Degrees and triangles		1999-09-09
		Sandra Mills pose la question : Are there any triangles which are not 180 degrees? I am also in need of information on the history of degree measure for an angle. Walter Whiteley lui répond.
	A Trigonometry Question		1999-08-28
		Diane Simms pose la question : My question is can the following be factored. I am a teacher who needs the factors to this right away. 2 Sin2X + 2 SinX CosX - 1= 0 Harley Weston lui répond.
	From an airport control tower		1999-08-04
		Pammy pose la question : Hi I am a 30 yo mature age student doing my HSC but am having difficulty understanding this, if you can help me. From an airport control tower, a Cessna bears 023 degrees T and is 27km away. At the same time, a Boeing 767 bears 051 degrees T and is 61km from the tower. Both planes are at the same height. i) What is the size of angle ATB? ii) Using the cosine rule to calculate the distance the planes are apart, to nearest kilometre. I figured out and drew the triangular diagram but can't figure out the rest and which formula to use. sorry about this, thankyou kindly Harley Weston lui répond.
	Sin 4A		1999-06-22
		Ryan Cochrane pose la question : If sinA = 4/5, and A is a first quadrant angle, find sin4A Harley Weston lui répond.
	A trig problem		1999-06-03
		Stu Barnes pose la question : cos(theta) / 1+ sin(theta)=sec(theta)-tan(theta) I've being having trouble with this one on my correspondance course. Harley Weston lui répond.
	Dig digs in the garden		1999-02-11
		Katherine Shaw pose la question : A circular garden has an a radius of 8m. Dig, the dog, is tied up to a fence that runs round the outside of the garden. Dig was able to dig up all the garden, apart from an area of 64 square metres, which he couldn't reach. How long was his lead? Chris Fisher and Harley Weston lui répond.
	A trig limit		1998-11-14
		Amy Atwell pose la question : what is the limit of of tanx / x + sin x as x approaches 0 Harley Weston lui répond.
	A Calculus Problem		1998-06-28
		Lorraine pose la question : I'm a post-secondary student taking calculus by correspondence. I'm stuck on the following question (and similar ones) Can you help? Evaluate the following indefinite integral: d(theta) ---------- 1 + sin (theta) (It says to multiply both numerator and denominator by: 1 - sin(theta) Thanks Lorraine Harley Weston lui répond.
	A trig limit		1998-05-28
		Ann pose la question : This problem is a calculus 1 limit problem-high school level. I'm teaching myself calc over the summer and I'm already stumped. find the limit lim sec^(2)[(sqrt2)(p)]-1 p-->0 --------------------- 1-sec^(2)[(sqrt3)(p)] I'm Ann. Harley Weston lui répond.
	Trigonometry history		1998-05-26
		Joeseph Huckler pose la question : Can you please tell me some history of the trigonometric ratio Tangent? who discovered it? when was it discovered and some other useful info... Penny Nom lui répond.
	Trigonometric functions		1997-12-21
		Calvin Cheng pose la question : My name is Calvin and I have a year 12 question for you to help me with. From a point S, the angle of elevation of the top of a tower due north of it is 20 degrees. From R, due east of the tower, the angle of elevation is 18 degrees. S and R are 100m apart. Find the height of the tower. Harley Weston lui répond.
	Cos(x) Cos(2x) Cos(4x)=1/8		1997-09-24
		Tan Wang pose la question : How many distinct acute angles x are there for which cosx cos2x cos4x=1/8? Chris Fisher Harley Weston and Haragauri Gupta lui répond.
	A Trigonometric Limit		1997-09-18
		Brian Ray pose la question : What is the limit, as x approaches 0, or tan^23x/x^2? (read, tan squared 3x over...)? Harley Weston lui répond.
	Finding the Mine		1997-06-23
		Billy Law pose la question : Tom is gold prospector. On his last trip out from town, he headed 35 degree South of West to a lake where he had lunch. The lake was 24 km out of Town. He then headed due East for 35 km before Doubling back on bearing of 15 degree South of west for 20 km to reach his mine. By converting to Cartesian coordinate before doing vector additions do the following: a) Calculate the position of the mine from town in term of a distance and a direction. ... Harley Weston lui répond.
	A problem with arccos.		1997-06-09
		Vanessa Chan pose la question : Prove: arc cos4/5 + arc cos (-5/13) = arc cos (-56/65) Harley Weston lui répond.
	Solving a Trig Equation.		1997-04-28
		Susan Harvey pose la question : Hi I am a teacher and have a calculus problem that I have a solution to but it seems so involved that I would be interested to see if their were other solutions. Solve for x, if x is from -90 to 90 degrees tan2x = 8cos{squared}x - cotx Chris Fisher Denis Hanson and Harley Weston lui répond.
	A trig problem		1996-12-13
		S. Johnson pose la question : sin t + cos t = 1/5. Find ALL exact values of cot t, given the original equation. Harley Weston lui répond.
	Trigonometry		1996-11-12
		Evans pose la question : Any idea who came up with some or most of the ideas involved in trigonometry? Chris Fisher lui répond.
	Height of a Hotel		1996-11-07
		Irene pose la question : "Irene" is to determine the # of floors in a hotel 500 feet up the street. Irene is on the 10th floor of an office building and can measure the angle of elevation to the top of the hotel, 57 degrees. Her view of the entire building is obstructed. If the street rises at an angle of 8 degrees from the office building to the hotel and the average distance between floors is 11 feet, how many floors are on the hotel? Penny Nom lui répond.
	The diameter of the sun.		1996-10-29
		Lynda Mow pose la question : What is the process for solving the following question? As viewed from earth, the sun subtends an angle of approx 32'. If the sun is 93,000,000 miles from earth, find the diameter of the sun. Penny Nom lui répond.
	A trig identity		1996-03-11
		Azmat Hussain pose la question : Is there an easier/another way to prove the trig identity cos(a+b) = cos(a)cos(b)-sin(a)sin(b)? Penny Nom lui répond.
	Trig identities		1995-11-30
		Azmat pose la question : Why do we work on the two sides of a trig identity separately? Harley Weston lui répond.

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