$\frac{\sin\left(x\right)}{\cos\left(x\right)-\sin\left(x\right)}=\cot\left(x\right)+1$

$\frac{x^5+2x^3-x^1-8}{x^2-2x+1}$

$\frac{\cos\left(2x\right)}{\sin\left(x\right)}\:=\:\frac{\cot\:^2\left(x\right)-1}{\csc\left(x\right)}$

$u^2-22u+121$

$\int y^3.sin\left(y\right)dy$

$\int\frac{t^{2}}{\left(t^{2}+4\right)^{4}}dt$