$\frac{x^3-1}{x^2-4}$

$2x+3<3-x$

$\log\left(\frac{\left(\sin\left(x\right)\right)^2\left(\tan\left(x\right)\right)^4}{\left(x^2+1\right)^2}\right)$

$\frac{x^2+6x+8}{x+3}$

$\int\:x^3\:\left(x^4\:+\:2\right)^3\:\:dx$

$\frac{\left(x^3-\:9x^2\right)}{3x^2}$

$\frac{1+\cot\left(z\right)}{1+\tan\left(z\right)}=\cot\left(z\right)$