$\frac{1}{\cos^2\left(x\right)}+\left(1+\tan\left(x\right)\right)\cdot\left(1-\tan\left(x\right)\right)$

$cot\left(90-\theta\right)=tan\:\theta$

$\frac{m^3+27n^3}{m-3n}$

$16\:-\:\left(16\:-\:9x\right)\:-\:8x$

$\frac{\left(3x^2+1\right)\cdot\left(3x^2-1\right)}{\left(6x+1\right)\cdot\left(6x-1\right)}$

$\frac{d}{dx}\left(x^2+y^9=16\right)$

$\int_{y^2-4}^5\left(x+2y\right)dx$