# If f(x) = 4x -2 and g(x) = e^(-x-1), what is f'(g(x)) ?

Apr 16, 2017

$f ' \left(g \left(x\right)\right) = 4$

#### Explanation:

First, take the derivative of $f \left(x\right)$:

$f ' \left(x\right) = 4$

Now plug in $g \left(x\right)$ in for $x$ in $f ' \left(x\right)$. However, there's no $x$. So that means that:

$f ' \left(g \left(x\right)\right) = 4$