$csca\:\left(1-cos2a\right)$

$\frac{x}{x^2+x-20}$

$\frac{\sec\left(x\right)\cos\left(x\right)}{\csc^2\left(x\right)}=\sin^2\left(x\right)$

$\lim_{x\to-0.9}\frac{\tan\left(-0.9\right)}{\sin\left(-0.9\right)}$

$\int3x^8dx$

$\int\frac{arcsin\left(x\right)}{x}dx$

$\frac{125}{-25}$