$\int-15dx$

$\cot\left(x\right)+\tan\left(x\right)=\tan\left(x\right)\cdot\sin^2x^{-2}$

$\left(m-2\right)\left(m+6\right)$

$\left(5-\frac{f}{3}\right)^2$

$\frac{dy}{dx}=\frac{e^x-xy\left(x+2\right)}{x}$

$\frac{3x^4-35x^2-9x+4}{x+3}$

$\lim_{x\to0}\left(\frac{2^x-2^{-x}}{sen\left(x\right)}\right)$