Let's see $ifwe$ can solve

${\displaystyle \underset{\phantom{}}{\overset{\phantom{}}{}}}(3ta{n}^{2}x-6tanx)se{c}^{2}xdx$

$u=$

$du=$

$In$ the next three boxes: first rewrite the integral $in$ terms $ofu,$ then take the antiderivative,

then rewrite the answer $in$ terms $ofx.$

${\displaystyle \underset{\phantom{}}{\overset{\phantom{}}{}}}(3ta{n}^{2}x-6tanx)se{c}^{2}xdx={\displaystyle \underset{\phantom{}}{\overset{\phantom{}}{}}}\frac{?}{b}=ar()=$