 |
|
|
|
|
|
|
|
|
Multinomial coefficients |
1999-12-03 |
|
From Suraj Das:
Is there a formula for the expansion of (a+b+c) to the nth power? Does it have to do with Pascal's triangle?
Answered by Penny Nom. |
|
|
|
|
|
|
The chain rule |
1999-12-03 |
|
From Jennifer Stanley:
This problem is making me dizzy. I would greatly appreciate a little help! Express the derivative dy/dx in terms of x. y=u^2(u-u^4)^3 and u=1/x^2
Answered by Harley Weston. |
|
|
|
|
|
|
Log Cancel |
1999-12-03 |
|
From Justin Murray:
Ok I feel like a goof because I know this and I cant think of an answer But I want to isolate the x in the function y=2^x how do I do this?
Answered by Harley Weston. |
|
|
|
|
|
|
Whole numbers |
1999-12-02 |
|
From Patty:
I'm in a 5th grade class, please explaine what whole numbers are.....
Answered by Penny Nom. |
|
|
|
|
|
|
The elimination method |
1999-12-02 |
|
From Jennifer:
Could I get an answer to this one: 2x+5y=36
3x+2y=32 I have to use the Elimination method, as I already know how to do Substitution. How do I begin and show my work? I'm attempting to eliminate the values for y.
Answered by Penny Nom. |
|
|
|
|
|
|
Zero to the zero |
1999-12-02 |
|
From A middle school teacher:
I am a middle school teacher who is looking for a precise explanation of why zero raised to the zero power is undefined. I am hoping to get an explanation using something other than the fact that diividing by zero is undefined.
Answered by Penny Nom. |
|
|
|
|
|
|
Camels and bananas |
1999-12-02 |
|
From Marie Rich:
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?
Answered by Claude Tardif. |
|
|
|
|
|
|
Get rich quick |
1999-12-02 |
|
From Holly Hutson:
If one cent were placed in an investment that doubles in value every day, what would be the value of the investment at the end of 30 days?
Answered by Penny Nom. |
|
|
|
|
|
|
Two calculus problems |
1999-12-01 |
|
From O'Sullivan:
Question #1 Assume that a snowball melts so that its volume decreases at a rate proportional to its surface area. If it takes three hours for the snowball to decrease to half its original volume, how much longer will it take for the snowball to melt completely? It's under the chain rule section of differentiation if that any help. I've set up a ratio and tried to find the constant but am stuck. Question #2 The figure shows a lamp located three units to the right of the y-axis and a shadow created by the elliptical region x^2 + 4y^2 < or= 5. If the point (-5,0) is on the edge of the shadow, how far above the x axis is the lamp located? The picture shows an x and y axis with only the points -5 and 3 written on the x axis. the lamp is on the upper right quadrant shining down diagonally to the left. There's an ellipse around the origin creating the shadow. It's formula is given as x^2 + 4y^2=5.
Answered by Harley Weston. |
|
|
|
|
|
|
Cos x = -1/2 |
1999-12-01 |
|
From Pierre Boivin:
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.
Answered by Penny Nom. |
|
|
|
|
|
|
An area problem |
1999-11-29 |
|
From Vicky Birch:
The length of a rectangle is three times it's breadth. If the length were 6 meters less, and the breadth were 6 meters more, the rectangle would be a square. Make a mathematical model and solve the resulting equation to find the breadth of the original rectangle. What is the area of the square?
Answered by Penny Nom. |
|
|
|
|
|
|
Two candles |
1999-11-24 |
|
From Skip Simpson:
You have two candles the same length. They are lit at the same time. One burns down in 4 hours; the other in 5 hours. How long does it take before one candle is three times the length of the other candle?
Answered by Walter Whiteley. |
|
|
|
|
|
|
The number of city blocks in a country mile |
1999-11-24 |
|
From Gloria Hearst:
For years my family has had an on going debate on the number of city blocks in a country mile. We vary from a minmum 8 blocks per mile to a maximum of 12 blocks per mile.
Answered by Nadine Griffiths and Penny Nom. |
|
|
|
|
|
|
How wide is the well? |
1999-11-24 |
|
From Chris Baranski:
There is a well and in the well there are 2 sticks one is 2 meters long the other is 3 meters long and they are opposite to each other. They are leaning against the wall of the well. The place where they touch is 1 meter of the bottom of the well. How wide is the well?
Answered by Chris Fisher. |
|
|
|
|
|
|
ln(x+3)+ln(x+2)=ln(x+11) |
1999-11-24 |
|
From Thibault Portevin:
"Résolvez l'équation : ln(x+3)+ln(x+2)=ln(x+11)" Je suis bloqué, pourriez-vous m'aider?
Answered by Claude Tardif. |
|
|
