$secx\left(1+cosx\right)\left(1-cosx\right)$

$\left(\frac{1}{2}-x^6\right)\left(\frac{1}{4}-\frac{x^6}{2}+x^{12}\right)$

$6\left|x+1\right|+2\left|x-4\right|$

$\lim_{x\to1.9}\left(\frac{x^2-5x+6}{x-2}\right)$

$\int_2^4-\frac{1}{x^2-6x+5}dx$

$\int x^3e^{-6x}dx$

$\frac{\left(18a^3\:+18a^2+27a\right)}{9a^2}$