$e^{x^2}=4$

$\lim_{x\to0}\left(\frac{e^x-e^{-x}}{in\left(1\:+\:x\right)}\right)$

$\int\:\left(x^2+3x-1\right)e^{2x}dx$

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

$\lim_{x\to1}\frac{\left|x-1\right|}{x^2-1}$

$\frac{tan^2x-sec^2x}{cos^2x}=-sec\left(x\right)$