You probably got the derivative wrong.. it's
Filling in yields the desired result.
Don't know if this is the right section. Sincerely hope so.
I'm having trouble with this problem (I'll try to translate it right...).
The edge of a cube measures x/2 - 1, in cm. Determine the rate of change in volume for x = 10.
I tried to find the derivative of [(x/2 - 1)^3] and then the result of x = 10, but I didn't get 24 cm3 per 1 cm, which is the right answer. I'ld like to know what I'm doing wrong.