AP Calc AB questions

dwarfwarri
Wed, 15 Dec 2010 09:48:30 +0000

Hi guys,

I have tried over and over but I still can’t find out how to do these questions:

1. A cube is expanding so that its surface area is increasing at a constant rate of 4 square inches per second. How fast is the volume increasing at the instant when the surface area is 24 square inches?
answer is 2cubic in/sec


What is the approximate slope of the tangent to the curve x^3+y^3=xy at x = 1? Calculator allowed
answer is -1.014
Water is flowing into a spherical tank with a 6 foot radius at the constant rate of 30pi cubic feet per hour. When the water is h feet deep, the volume of water in the tank is given by the formula:V= ((pih^2)/3)(18-h)
Determine the rate (in ft per hr) that the depth of the water in the tank is increasing at the instant when the water is 2 feet deep.
answer is 1.5


For questions 2 and 3 I’m allowed to use a calculator but I really don’t know how I can use it for these questions.

Please help!

Thanks!!!

Sorry, I just figured out that I forgot to put the pi in question 3 when I was doing it, so i couldn’t get the right answer. But I’m still having trouble with question 1 and 2 please help!