## Calculus, 10th Edition (Anton)

$=\frac{2}{5}x.$
Distribute the $\frac{1}{5}$ through the $x^{2}+1$ to get $\frac{1}{5}x^{2}+\frac{1}{5}$. Finally, use the power rule for derivatives ($[x^{n}]'=nx^{n-1}$) to get $\frac{2}{5}x^{2-1}+0=\frac{2}{5}x.$