$\int\left(\frac{cos^2x}{cos}\right)dx$

$\int\left(\frac{\tan\left(5x\right)}{\cos^2\left(5x\right)}\right)dx$

$\lim_{x\to-3}\left(\frac{3x+9}{\sqrt{x+7}-2}\right)$

$\left(121-66d+36d^2\right)\left(11+6d\right)$

$\frac{-52}{-52}$

$1-\cos2\left(x\right)+2\sin^2\left(x\right)=2$

$\int te^{-3t}\:dx$