Let `F(x)=f(f(x))` and `G(x)=F(x)^2` . Knowing `f(4)=5, f(5)=3, f'(5)=8` and `f'(4)=5` , find `F'(4)` and `G'(4).`

1 Answer | Add Yours

degeneratecircle's profile pic

Posted on

We need the chain rule for both. According to that, we get

`F'(4)=f'(f(4))*f'(4)=f'(5)*f'(4)=8*5=40` and

`G'(4)=2F(4)*F'(4)=2*f(f(4))*40=2*f(5)*40=6*40=240.`

We’ve answered 333,441 questions. We can answer yours, too.

Ask a question