#### Answer

$$f'\left( x \right) = \pi {x^{\pi - 1}}$$

#### Work Step by Step

$$\eqalign{
& f\left( x \right) = {x^\pi } \cr
& {\text{evaluate the derivative}} \cr
& f'\left( x \right) = \frac{d}{{dx}}\left( {{x^\pi }} \right) \cr
& {\text{general power rule}} \cr
& \frac{d}{{dx}}\left( {{x^p}} \right) = p{x^{p - 1}},{\text{ }}p = \pi \cr
& then \cr
& f'\left( x \right) = \pi {x^{\pi - 1}} \cr} $$