# Math Help - find h'(2)..

1. ## find h'(2)..

Suppose f'(2)=3, f'(5)=4 and let h(x) be the composite function h(x)=f( $x^2$+1). Find h'(2).

Do I need a formal proof and stuff?

2. Originally Posted by tn11631
Suppose f'(2)=3, f'(5)=4 and let h(x) be the composite function h(x)=f( $x^2$+1). Find h'(2).

Do I need a formal proof and stuff?
all you need is the chain rule ...

$h(x) = f(x^2+1)$

$h'(x) = f'(x^2+1) \cdot 2x$

$h'(2) = f'(5) \cdot 4$

3. The reason I asked if it need a proof, and posted in the analysis section was because its out of an into to applied analysis book..but thank you!