Posted by lan on Sunday, July 10, 2011 at 4:25am.
The altitude of a triangle is increasing at a rate of 2500 centimeters/minute while the area of the triangle is increasing at a rate of 4000 square centimeters/minute. At what rate is the base of the triangle changing when the altitude is 11500 centimeters and the area is 89000 square centimeters?Note: The "altitude" is the "height" of the triangle in the formula "Area=(1/2)*base*height". Draw yourself a general "representative" triangle and label the base one variable and the altitude (height) another variable. Note that to solve this problem you don't need to know how big nor what shape the triangle really is.

CAL  Damon, Sunday, July 10, 2011 at 6:52am
A = .5 b h
dA/dt = .5 b dh/dt + .5 h db/dt