







Solve the equation completely cos 2x = 1 
20170608 

Lava pose la question : Solve the equation completely cos 2x = 1 Penny Nom lui répond. 





The derivative of x^1/3 
20151108 

omar pose la question : hi can help me
am teacher ask me about x^1/3 Derivation definition . Penny Nom lui répond. 





Is a square a trapezoid? 
20150126 

Katie pose la question : Can a trapezoid sometimes be a square? Penny Nom lui répond. 





Rates, percentages and units 
20141230 

Kenneth pose la question : Hello:
If percentages have no units, why are some percentages called rates, as in interest rate, or
perhaps a tax rate of 7% as an example? A rate has units of different quantities.
I thank you for your reply. Robert Dawson lui répond. 





Planar curves 
20141213 

ann pose la question : what does planar curve mean in your definition of a cone? Penny Nom lui répond. 





Trig functions and the unit circle 
20141002 

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. 





Tangent of theta 
20120117 

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. 





The derivative of f(x) = (x+1)^1/2 
20110905 

Carla pose la question : Find the derivative using the limit process of
f(x) = (x+1)^1/2 Harley Weston lui répond. 





Using the limit definition 
20100606 

Meagan pose la question : Using the limit definition find the derivative of 3/(2x^2) Harley Weston lui répond. 





Differentiating y= square root(x1) 
20090929 

edith pose la question : describe the xvalues at which f is differentiable.
y= square root(x1) Penny Nom lui répond. 





Vector spaces 
20090705 

Nazrul pose la question : How can I prove that m(a+b)=ma+mb where a and b are two vectors.
Thank you. Harley Weston lui répond. 





The derivative using limits 
20090421 

Kirstin pose la question : I am trying to take the limit of f(x) = [f(x+h)f(x)] / h
If you try taking the limit by substituting the limiting value h=0, you get 0/0,
which of course is not the right answer. You rewrite f(x+h)f(x) so it has a factor
of h in it, which you cancel with the h in the denominator before you substitute h=0.
But I am not sure how to do this. Thanks. Robert Dawson lui répond. 





A rectangular prism 
20090113 

nika pose la question : How many bases does a rectangular prism have? What are they? Harley Weston lui répond. 





The definition of the sine function 
20071122 

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. 





The derivative of f(x)=1/(x1) 
20070921 

Michelle pose la question : im having trouble finding the derivative of f(x)=1/(x1) using the f(x+h)f(x)/h method. Stephen La Rocque lui répond. 





Trig functions for angles not between 0 and 90 degrees 
20070716 

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. 





Inclusive definitions 
20051214 

Layla pose la question :
recently the solvable quandary of 5+5+5=550 came up (the question says that you have to put 1 straight line somewhere in the equation to make it true with out turning the "=" into a "not=" sign).
So two answers were put forward:
545+5=550 (the use of a line converting a + into a 4)
AND
5+5+5(less than or equal to)550
There is currently an argument about the second solution. The disagreement is about whether this sign can be used. One person is arguing that the "less than or equal to" sign defines that the number on the left is in the range 550 and below. The other is saying that since the number (which is clearly defined with no variables) can never equal 550, then the "less than or equal to" sign cannot be used in this case.
Which one is the correct definition?
Walter Whiteley lui répond. 





Is a square a rectangle? 
20041121 

Carol pose la question : I am a teacher. In an FCAT sixth grade review test, there was a question to the students to draw a square and then they referred to it as a rectangle.
What is the definition that makes a rectangle a square that can be taught to the students without confusing them. Walter Whiteley lui répond. 





The sides of a circle 
20040107 

Helena pose la question : My name is Helena and I am 10 years old. On a resent math exam I was asked
the question" How many sides does a circle have?" and I wrote down none. The
teacher said the answer was one side. Chris Fisher lui répond. 





Definitions and descriptions 
20030608 

Tammy pose la question : MY DAUGHTERS TEACHER ASKED HER TO GIVE BOTH A DESCRIPTION AND A DEFINITION OF THE FOLLOWING ... CIRCLE, SQUARE, TRIANGLE,HEXAGON...... THE LIST GOES ON. WHAT IS THE DIFFERENCE BETWEEN DEFINITION AND DESCRIPTION ? DO A CIRCLE FOR AN EXAMPLE PLEASE. Penny Nom lui répond. 





The vertex of a cone 
20030327 

Holly pose la question : I read your response to Callie about whether a cone has a vertex or not. Is it ONLY a vertex if both halves of the cone are together or can one half of the illustration have a vertex? Walter Whiteley lui répond. 





Can a square be a rhombus? 
20030304 

Beth pose la question : Can a square be a rhombus? Some sources say yes, some say no. Some sources define a rhombus as a quadrilateral and parallelogram with equal sides, but without right angles. Some sources say a square is a special case of a rhombus. Clarity, please! Walter Whiteley lui répond. 





A polygon 
20010911 

Sueling pose la question : what is the smallest polygon. what is a polygon. Penny Nom lui répond. 





A prism 
20010118 

Nigel Ayling pose la question : What is the mathematical definition of a prism, I am confused by the following definitions as they appear to be contradicto... Walter Whiteley lui répond. 





Is a square a rectangle? 
20000215 

Jaireh pose la question : This is something that aroused a debate in class: A rectangle was defined as a parallelogram with 4 right angles. A square was defined as a parallelogram with 4 congruent sides and 4 right angles. I need written and conclusive proof that some rectangles can or cannot be squares. I tried insisting that some of them can.. but without proof nobody will listen. Walter Whiteley lui répond. 





Pyramids and prisms 
20000118 

Tyler pose la question : What's the definition of a Triangular Prism and a Triangular pyramid. Penny Nom lui répond. 





Algebra 
20000118 

Candis pose la question : I want to know what exactly is Algebra? Not how to do it, or methods. Just what is it? Allen Herman lui répond. 





Isosceles triangles 
19991012 

Amber pose la question : In defining the types of triangles, our class was stumped by a question asked by one of the student. Maybe you could help. The definition of an equilateral triangle is a triangle with three congruent sides. The definiton of an isosceles triangle is a triangle with at LEAST two congruent sides. The question is, if an isosceles triangle only requires at Least two of the sides to be congruent, could an equilateral triangle be called an isosceles triangle? Penny Nom, Walter Whiteley and Chris Fisher lui répond. 

