 |
|
|
|
|
|
|
|
|
Adding consecutive numbers |
2006-04-26 |
|
From Lisa:
When I have a total that is the sum of consecutive numbers, how do I figure out what the numbers are?
Answered by Stephen La Rocque. |
|
|
|
|
|
|
What defines a pyramid? |
2006-04-25 |
|
From Julie and son:
My son and I think that a pyramid can have any number of sides, but my son's teacher says a pyramid has just 4 sides (including the base). Who's right?
Answered by Stephen La Rocque. |
|
|
|
|
|
|
Absolute Value vs. Standard Deviation ? |
2006-04-24 |
|
From Sonia:
Why we don't just take the average of the absolute value of difference scores (use the mean deviation) to describe variability instead of calculating the standard deviation?
Answered by Claude Tardif. |
|
|
|
|
|
|
How do I find the percentage interest? |
2006-04-24 |
|
From Cheryl:
Kiera invested $43,608 in a mutual fund that paid
$432.96 in interest at the end of the year. What was the percent interest Kiera earned from her initial investment?
Answered by Stephen La Rocque. |
|
|
|
|
|
|
How many gallons in a cubic foot? |
2006-04-24 |
|
From Jana:
How many gallons in a cubic foot?
Answered by Stephen La Rocque. |
|
|
|
|
|
|
Volume d'un cône |
2006-04-24 |
|
From Christelle:
Caroline décide de se servir de ses connaissances mathématiques pour "rouler" son petit frère: "Arthur, dit-elle, je te propose que nous mettions chaucun un euro dans l'achat d'un cône glacé. Je mangerai la première, jusqu'à mi-hauteur, et toi, tu auras la seconde moitié."
Combien la part de Caroline représenterai-elle par rapport à celle de son petit frère s'il acceptait ?
Answered by Claude Tardif. |
|
|
|
|
|
|
Proof by induction |
2006-04-24 |
|
From Meshaal:
Find an expression for:
1-3+5 - 7 + 9 - 11 + ... + (-1)^(n-1) * (2n-1)
and prove that it is correct.
Answered by Stephen La Rocque. |
|
|
|
|
|
|
Geometry proof |
2006-04-23 |
|
From Jade:
From a point P outside a circle with centre O, tangents are drawn to meet the circle at A and B.
a) Prove that PO is the right bisector of the chord AB.
b) Prove that
Answered by Stephen La Rocque. |
|
|
|
|
|
|
Finding the supplementary angles |
2006-04-22 |
|
From Kendra:
Angles ABC and DBA are supplementary. If m
Answered by Stephen La Rocque. |
|
|
|
|
|
|
What's the difference between percentages and points? |
2006-04-21 |
|
From Sayed:
What is the difference between percentages and points?
Answered by Stephen La Rocque. |
|
|
|
|
|
|
The perimeter of a regular octagon |
2006-04-20 |
|
From Martin:
I would like to make an octagon out of 2x4 lumber. I know that the lumber needs to be cut at 67.5 degree angles, but how do I determine the length of each piece if I want to make, say, a 2.5 ft diameter octagon?
Answered by Stephen La Rocque. |
|
|
|
|
|
|
What is the surface area of a cone with a hemisphere on top? |
2006-04-20 |
|
From Jordan:
How do you find the surface area of a cone with a hemisphere on top? The only information I have is the radius of the hemisphere, which is 4, and the total height, which is 7.
Answered by Stephen La Rocque. |
|
|
|
|
|
|
Distance to the horizon |
2006-04-20 |
|
From Raymond:
If I stand on the edge of the sea on a beach and look into the horizon, is there a way or formula for calculating the distance from myself to the horizon?
Answered by Stephen La Rocque. |
|
|
|
|
|
|
Geometric sequence and basic functions (graphs) |
2006-04-20 |
|
From Marlene:
Which of the basic functions is related to the geometric sequence:
Linear, Quadratic, Rational, or Exponential?
Can you give me an example of how it would be used in normal life?
Answered by Stephen La Rocque. |
|
|
|
|
|
|
What is the original cost? |
2006-04-19 |
|
From Charlie:
Selling a piece of furniture for $670 and the profit is 35%. What is the original cost?
Answered by Stephen La Rocque. |
|
|
