$2x+11x+11$

$\lim_{x\to0}\left(\frac{e^{\left(1-ax\right)}-e}{\sin\left(ax\right)}\right)$

$\int\:\frac{\cos\:\left(x\right)}{1-\cos\:\left(x\right)+\sin\:\left(x\right)}dx$

$\left(4x^2+3x^4\right)^2$

$y'=2y-4$

$x^2-\left(3x-1\right)^2$

$\frac{1}{csc\left(a\right)-1}-\frac{1}{csc\left(a\right)+1}=2\tan^2\left(a\right)$