$\frac{x-1}{x^3+x}$

$\int_0^{\frac{n}{3}}\left(sen2xcos4x\right)dx$

$\tan\left(a\right)\cdot\cot\left(a\right)\cdot\sin^2\left(a\right)$

$\frac{x+y}{x-y}-\frac{x-y}{x+y}$

$\frac{3x^3+9x^2+6x+12}{3x+3}$

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

$45s^2+18s+1=0$