$14-\left(25+50\right)+36$

$\frac{1}{1-\sen^{2}\theta}=1+\tan^{2}\theta$

$\left(-2\right)^2-1$

$x^2+4\le4x$

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

$\int cos7xsen2xdx$

$\frac{1}{\sin\left(x\right)+\frac{\cos\left(x\right)^2}{\sin\left(x\right)}}$