32 articles trouvés pour ce sujet.
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il y a deux contenant |
2007-01-23 |
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Eric pose la question : il y a deux contenant un de 3 litre et un de 5 litre les deux sont vide comment en les remplisant on peux obtenire 4 litre Claude Tardif lui répond. |
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Matrice |
2006-02-01 |
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Kader pose la question : mon probleme est le suivant soit deux matrices carrees A et B d'ordre n qui sont anticommutatives AB= -BA , demontrer que au moins une des deux matrices n'est pas inversible si n est impair.
je n'arrive pas a utiliser le fait que n soit impair, trouver le rapport entre n impair et inverse des matrices, je pars sur la base de DETAB=DETA*DETB Claude Tardif lui répond. |
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Finance charge |
2019-01-03 |
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Kenneth pose la question :
Hello Math Central:
The calculation for determining the finance charge per $100.00 (FC/100) is determined by the following:
Finance Charge/Amount financed * $100.00 = the finance charge per $100.00
Since the denominator (amount financed) is not multiplied by $100.00, how does the result equal the finance charge per $100.00? The numerator (finance charge) is the only amount multiplied by $100.00.
Example 1. 3/4 * 6 = 18/4 not 18/24 The 4 is not multiplied by the 6.
Example 2. $49.00/$200.00 * $100.00 If $49.00 is divided by $200.00 the result is $0.245/$1.00. If $0.245/$1.00 * $100.00 = $24.50/$1.00. This answer is not $24.50/$100.00.
How does the above equal the finance charge per $100.00 when the denominator is not multiplied by $100.00?
If the division is not used to indicate the $0.245 per $1.00, the result becomes $49.00/$200.00 * $100.00 = $4,900.00/$200.00.
I thank you for any helpful reply.
..........
Kenneth
Penny Nom lui répond. |
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The intersection of a curve and a line |
2018-03-08 |
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lola pose la question : find the set of values of constant C for which the line y=x+c intersects the curve y=2 square root x at, at two distinct points Penny Nom lui répond. |
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The evaluation of a 3 by 3 determinant |
2016-02-19 |
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Kristen pose la question : What is the step-by-step process on how to evaluate the determinant of a 3*3 matrix, using the expansion method (not the diagonal method) Penny Nom lui répond. |
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Fractions of two quantities |
2016-01-22 |
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Melody pose la question : Kate ate 1/4 of her orange. Ben ate 2/4 of his banana. Did Kate and Ben eat 3/4 of theit fruit? Explain. Penny Nom lui répond. |
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The quadratic formula |
2013-01-03 |
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itsel pose la question : Find the discriminant ans use it to determine the use the quadratic formula to solve the equasion -2x^2+3x+2=0 Penny Nom lui répond. |
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The discriminant |
2010-01-17 |
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Sonjonnia pose la question : What is the value of the discriminant?
16x^=16x-4 Penny Nom lui répond. |
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The adjacency matrix of an undirected graph |
2010-01-15 |
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Bhavya pose la question : Let Cn be the undirected graph with vertex set V = {1,2,3,...,n} and edge set E = {(1,2), (2,3), (3,4),.... , (n-1,n), (n,1)}. Let An be the adjacency matrix of Cn.
a. Find the determinant of An.
b. Find (An)^2 Robert Dawson lui répond. |
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An annuity |
2009-02-27 |
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Jules pose la question : R 20 000 is deposited in the bank,at the end of each year R 5 000
is withdrawn from it, the interest is 13 percent compounded monthly.
Calculate how many years that person will be able to use his/her money ? Stephen La Rocque lui répond. |
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Nullity |
2009-02-16 |
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Justin pose la question : What exactly does the term nullity mean in the context of transreal numbers invented by Dr. James Anderson?
Thanks for your help in answering this question!
All the Best,
Justin Robert Dawson lui répond. |
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4 by 4 determinants |
2008-06-27 |
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rav pose la question : How to solve problems of determinants which has four rows and four columns& please give me easy tips to solve permutations and combinations problems. Harley Weston lui répond. |
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Determinants |
2008-05-02 |
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Henry pose la question : I have a question about solving 3x3 matrices.
The traditional way, or at least the way I've been taught, is that if one has a 3x3 matrix such as:
[ a b c ]
[ d e f ]
[ g h i ]
one solves it according to this formula:
[ei - hf) - (bi - hc) + (bf - ec) = determinant.
According to a book I'm now studying to prepare for the California CSET exam, there is another, easier, way to solve it:
[ a b c ] [ a b ]
[ d e f ] [ d e ]
[ g h i ] [ g h ]
In other words, one repeats the first two rows of the matrix and adds them to the right.
At this point, the determinant is calculated thus:
(aei) +(bfg) + (cdh) - (gec) - (hfa) - (idb).
Is this, in fact, correct? Harley Weston lui répond. |
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Area of a 17-sided lot |
2007-11-21 |
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Lynda pose la question : My uncle is wanting to buy this piece of land [a 17-sided polygon] but we are questioning the acerage total. the measurements are [on the attached diagram]. Stephen La Rocque lui répond. |
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A matrix of polynomials |
2007-07-18 |
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Mac pose la question : can you please help me out to solve this ?
Let A be a n*n matrix, the elements of which are real (or complex) polynomial in x.
If r rows of the determinant becomes identical when x=a, then the determinant
A) has a factor of order r
B) has a factor or order > r
C) has no factor
D) has a factor of order < r Harley Weston lui répond. |
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Values of k for which k(x^2+2x+3) - 4x - 2 is never negative |
2007-06-29 |
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claire pose la question : Find the range of values of k for which k(x^2+2x+3) - 4x - 2 is never negative. Harley Weston lui répond. |
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The roots of (x - k)(1-3x) + 1 = 0 |
2007-06-28 |
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Claire pose la question : Show that the roots of (x - k)(1-3x) + 1=0 are real and distinct for all real values of k. Hence, or otherwise, find the range of 9sin^2 r - 6sin r + 13 Harley Weston lui répond. |
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Evaluating a determinant |
2007-02-25 |
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Suud pose la question : Please send me the detailed steps of calculating the determinant of the following 4by4 matrix -1 -3 1 2 -2 0 -1 1 3 2 0 4 0 -3 1 -2 Haley Ess lui répond. |
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My wife's recent pregnancy, |
2006-07-24 |
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Tom pose la question : During my wife's recent pregnancy, it so happened that my wife's 29th birthday fell on the exact same day that her unborn child was 29 weeks old (i.e. it was 29 x 7 days from the date of conception as advised by the doctor)
I would like to know what the probability is of the above event occurring for a randomly chosen pregnant woman i.e. that the pregnant mum's x'th birthday falls on the same day that the unborn child is x weeks old EXACTLY.
Stephen La Rocque lui répond. |
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Discriminant |
2005-06-20 |
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A student pose la question : If a quadratic has real root, its discriminant b2-4ac>=0 Is there any similar condition or method by which you can find whether roots of a cubic equation are real or not? Chris Fisher lui répond. |
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A matrix problem |
2005-04-04 |
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Alan pose la question :
Let A = |
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1 | -1 | 0 |
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2 | -1 | 2 |
a | b | c |
where a, b, c are constant real numbers. For what values of a, b, c is A invertible? [Hint: Your answer should be an equation in a, b, c which satisfied if and only if A is invertible.]
Judi McDonald lui répond. |
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Trading fish for bread |
2005-02-25 |
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Mike pose la question : Byron lives where people trade goods they produce for other things they
need. He has some fish and wants to trade them for bananas. He finds
the following:
5 fish = 2 loaves of bread
6 oranges = 2 melons
1 loaf of bread = 1 banana and 3 oranges
4 loaves of bread = 14 oranges
How many bananas can Byron get with 5 fish? Penny Nom lui répond. |
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A metric prefix table |
2004-03-07 |
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April pose la question : Can you tell me what the scale is for nano, micro, mega, kilo, etc.... I know that mega is 10 to the sixth power but I can't remember the other ones. Penny Nom lui répond. |
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A determinant |
2003-02-13 |
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A student pose la question :
I have to find the determinant of the following matrix -2 | 3 | 1 | 2 | 4 | -3 | 0 | -2 | 5 | 1 | 4 | 2 | 1 | -3 | 5 | 2 | 3 | 4 | -1 | 2 | 6 | 0 | 3 | 2 | -4 | Penny Nom lui répond. |
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Expanding determinants using minors |
2001-02-20 |
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A student pose la question : Question: 1) Determinants by expansion by minors. i) | 1 2 1 2 1 | | 1 0 0 1 0 | | 0 1 1 0 1 | | 1 1 2 2 1 | | 0 1 1 0 2 | Harley Weston lui répond. |
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Banana yogurt |
2000-11-03 |
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James pose la question : A grocery store has 100 cartons of banana yogurt in stock.Each carton contains 12 cup of banana yogurts.The probability that a cup has fewer than 20 banana chunks in it is 10 %. So,What is the probability that between 15 and 25 (inclusive) cartons out of the 100 cartons have exactly 3 cups with fewer than 20 banana chunks? Harley Weston lui répond. |
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Transporting bananas |
2000-10-18 |
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Krystie pose la question : A farm has 45 bananas, a man has to take a truck and transport 15 bananas to a market that is 15 miles away. Every mile he travels, he must eat a banana. I have to get at least one banana to the market Penny Nom lui répond. |
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Rule of 78 |
2000-03-22 |
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Dan Baumgarten pose la question : Can you explain the rule of 78 and the reverse rule of 78? Thanks. Claude Tardif lui répond. |
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order 4+ determinants |
1999-12-06 |
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Joe Kron pose la question : Why is it never shown how to calculate the value of 4x4 (or larger size) deteminants by the diagonal multiply methods that are generally shown for 2x2 and 3x3 determinants? The method I'm talking about is called Cramer's Rule??? Is this method not extensible to order 4+ and if not why not? Anyway the method always shown for order 4+ is called "reduction by minors" which is not the answer to this question. Walter Whiteley lui répond. |
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Camels and bananas |
1999-12-02 |
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Marie Rich pose la question : Corey Camel's harvest, worth its weight in gold, consists of 3000 bananas. The market place where the stash can be cashed in is 1000 miles away. However, Corey must walk to the market, and can only carry up to 1000 bananas at a time. Furthermore, being a camel, Corey eats one banana during each and every mile she walks (so Corey can never walk anywhere without bananas). How many bananas can Corey get to the market? Claude Tardif lui répond. |
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Area of a triangle from vertex coordinates |
1999-04-21 |
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Mark Tyler pose la question : I'm no schoolkid, but I liked your answers about triangles. You might enjoy a quick look at this, the kids may too. I was working on a Voronoi dual where I had to calculate the areas of very many triangles expressed as vertex coordinates, so I derived the following very direct formula: A = abs((x1-x2)*(y1-y3)-(y1-y2)*(x1-x3)) for triangle (x1,y1)(x2,y2)(x3,y3) I've never seen this in a textbook. Is it original? I doubt it, the proof is only a few lines long. Regardless, it may be fun for the kids, even if it's not on the curriculum. Walter Whitley lui répond. |
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Intersection of Planes |
1998-12-03 |
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Lindsay Fear pose la question : My name is Lindsay Fear. I am an OAC student (which is the Ontario equivalent to Grade 12 in most other states and provinces). I am in an Algebra and Geometry course and am currently studying a unit on equations of planes. Our teacher has given us this question that my friend and I have attempted several times, but we are still unable to solve it. My teacher has also suggested using the internet as a resource. The question is: Prove that a necessary condition that the three planes -x + ay + bz = 0 ax - y + cz = 0 bx + cy - z = 0 have a line in common is that a^2 + b^2 + c^2 + 2abc = 1 Walter Whiteley lui répond. |
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