$\frac{\left[1-cosx\right]}{tan\left[\frac{x}{2}\right]}$

$-18+2$

$y'+2xy=1+x^2+y^2$

$\int\cot^43xdx$

$\cos^2x\cdot\tan^2\left(x\right)+\sin^2\left(x\right)\tan^2\left(x\right)+1$

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

$sin\left(4x\right)=8sin\left(x\right)cos^3\left(x\right)-2sin\left(2x\right)$