$\cos\left(x\right)\left(\sin\left(x\right)+\cos\left(x\right)\cot\left(x\right)\right)$

$2a+6b-5a-14b-2$

$\int\left(\frac{1}{\left(x^2-16\right)^{\frac{3}{2}}}\right)dx$

$\left(15x+2\right)^2$

$\frac{d}{dx}\left(x^2\:sec\left(\pi-x\right)\right)$

$1+tan^2x=secx$