$\int\left(5\csc^2\left(x\right)\right)dx$

$\left(tanx\right)^2=secx+1$

$\frac{dy}{dx}=\frac{1}{2}\left(\frac{x}{y}\right)$

$\sqrt{x\left(x+2\right)}+x\left(x+1\right)-x^2-3x$

$\log\left(x-2\right)+log\left(x+6\right)=log\left(8x+33\right)$

$\left(81-x\right)\cdot\left(4-x\right)>x+11$

$\cos2x-\cos x=2$