## Calculus 8th Edition

$\tan x-x+C$
$\int\tan^2 x\ dx$ Use the identity $\sec^2 x=1+\tan^2 x$ to rewrite $\tan^2 x$ as $\sec^2-1$: $=\int(\sec^2 x-1)dx$ $=\boxed{\tan x-x+C}$