$\csc^2\left(a\right)-\cot^2\left(a\right)=1$

$\int_0^4\left(\sqrt{16-x^2}-\pi\right)dx$

$\frac{n}{n^5}$

$\int\frac{5}{x^2-2x-3}dx$

$\left(\tan\left(x\right)-\sqrt{3}\right)\left(2\cos\left(x\right)-1\right)=0$

$\frac{1}{tanx}+\tan\left(x\right)=\frac{1}{sinxcosx}$

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