Question

Let f be a differentiable function. Let F(x)=[ln f (3x)]^2 Then what if f'(x)?

Answer 1

just differentiate implicitly i would say.

Answer 2

assuming that F(x) is the antiderivative of f(x), then you would want to take the derivative twice
are you sure you typed this up right?

Answer 3

Then solve for f'

Answer 4

but the f in the problem is f(3x), not f(x)....

Answer 5

is F the antiderivative of f ???

Answer 6

No idea. it gave me 4 choices

a) 1/[f(3x)]^2
B) 2 ln f(3x) x f'(3x)/(3x)
C) 1/f(3x)^2
D) 6 ln f(3x) x f'(3x)/f(3x)

Answer 7

and you want f', not F', correct?

Answer 8

i think so

Answer 9

that's how my professor wrote it..

Answer 10

i don't know how to take that derivative cause there's an f.

Answer 11

you must be looking for F'(x) not f'(x) because F''(x) is not a choice

Answer 12

3?

Answer 13

i honestly don't know, i'm under a time limit for this homework and I also have one more question to ask

Answer 14

I can't give you the answer, I can only help you towards it

Answer 15

typo\[\frac d{dx}f(3x)=3f'(3x)\]