Question

If f(3) = 2 and f'(3)=5, find the instantaneous rate of change of g(x) with respect to x at x=3 if g(x)=f(x)/x^2

Someone please teach me how to do this question

Answer 1

Hi
Are you familiar with the quotient rule?

Answer 2

yes

Answer 3

Ok, so when you take the derivative of g(x), what do you get?

Answer 4

f'(x)*x^2 - f(x)(2x)/(x^2)^2

Answer 5

ok, so if we say x=3 you can plug it in and get what?

Answer 6

5(9)-2(6)/81

Answer 7

ok, so what's the final value?

Answer 8

11/27

Answer 9

Right =)

Answer 10

ohh.. I see.... Thank You ! :)

Answer 11

Sure, you're welcome =)