$\frac{1}{1-\cos\left(y\right)}+\frac{1}{1+\cos\left(y\right)}=2\csc\left(y\right)^2$

$\int\frac{x^2-5}{x\left(x+1\right)^2}dx$

$\lim_{x\toa}\left(\frac{x^{5}-a^{5}}{x^{4}-a^{4}}\right)$

$\lim_{x\to0}\left(4xcos2x\right)$

$\sin30+\csc^230-2\cot45$

$u^2+2u^2+u+2$

$\int ln\left(ex\right)dx$