Answer
$f(1) = 0$
$f'(1) = 5$
Work Step by Step
Using the formula:
$f'(1) = \lim_{h \to 0} \frac{f(1+h)-f(1)}{h} =\lim_{h \to 0} \frac{f(1+h)}{h}-\frac{f(1)}{h} =\lim_{h \to 0} 5-\frac{f(1)}{h} $
The problem statement gives that $f(x)$ is differentiable at $1$. Thus, $f(1)$ must be $0$ and $f'(1)$ is therefore $5$.
