$k=\frac{-2cos2xsenx+2cos4xsenx}{2sin3xsen2x}$

$12m^2-15m-35$

$\int_1^{\sqrt{e}}\left(xlnx\right)dx$

$\int\frac{-\sin^2\left(x\right)}{\cos\left(x\right)}dx$

$x^2-x+18$

$\int\left(x\left(x-4\right)^9\right)dx$

$\lim_{x\to0}\left(\frac{arcsin\left(x\right)-e^x+1}{4x^2+2x^3}\right)$