$\lim_{x\to3}\left(\frac{\sqrt{x}-\sqrt{3}}{\left(x+3\right)\left(x-3\right)}\right)$

$3mn^{10+2mn^2^2}$

$\frac{sen\left(x\right)\:cos\left(x\right)}{1\:-\:sen2\left(x\right)\:}$

$\int\frac{e^{-u}-4}{e^{-u}+4u}dx$

$\sqrt{6y}$

$\int\left(\frac{1}{x^3-x^2-9x+9}\right)dx$

$\left(y^2e^x-\cos\left(x\right)\right)dx+2ye^xdy=0$