To find the derivative of a composite function we use the chain rule
Then, we first find the derivatives of f and g. The function f is of the form
Then
On the other hand, the derivative of g is very simple
After doing this, we evaluate f' in g(x), and we have
Replacing f'(g(x)) and g'(x) we obtain
Finally, we evaluate this expression in x=1
Then, the answer is 8