Question

The volume of a cube is increasing at a rate of 9 cubic centimetres per
second. How fast is the surface area increasing when the length of an edge is 10
centimetres ?

Answer 1

@bob-bob-bob

Answer 2

V (cube) = a^3

d v / dt = 3 a^2 d a/ dt

Answer 3

9 = 3 a^2 d a /dt

3/ a^2 = d a/ dt


S = 6 a^2

d s/ dt = 6 * 2 a da / dt

Answer 4

a = 10.... just sunstistute and find the answer

Answer 5

Thanks :) @Yahoo!

Answer 6

Welcome..:)