Answer
$$F(x) = \pi^2x+C$$
Work Step by Step
Given $$f(x) = \pi^2= \pi^2x^{0}$$
Then by using if $f(x)=x^{\alpha}\ \to\ \ F(x) = \frac{x^{\alpha+1}}{\alpha+1}+C$
\begin{align*}
F(x) &= \pi^2x+C
\end{align*}
To check
\begin{align*}
F'(x) &= \pi^2\\
&=f(x)
\end{align*}
