## Calculus: Early Transcendentals (2nd Edition)

$\frac{10}{100x^{2}+1}$
Recall that $tan^{-1} x= \frac{1}{1+x^{2}}$ Then, using chain rule, we get $tan^{-1}(10x)= \frac{1}{(10x)^{2}+1}\cdot\frac{d(10x)}{dx}=\frac{10}{100x^{2}+1}$