$4^2-\left(-2\right)^2$

$\tan x^2=1$

$\lim_{x\to\infty}\left(x\cdot\sqrt{1-cos\left(\frac{\pi}{2x}\right)}\right)$

$\int_0^{\frac{\pi}{4}}\left(\frac{sec^2x}{\left(\tan\left(x\right)-1\right)^2}\right)dx$

$82z+25z-14z-7z$

$\lim_{x\to0}\left(\frac{2x^2-x^3}{x^5-2x}\right)$

$\frac{x^2+x-6}{x-2}$