$\lim_{x\to0}\left(\frac{sin\left(x\right)}{x^3+2x+1}\right)$

$\left(6x^3-4x^2+5x-2\right)\cdot\left(3x^3-4x^2+5x+3\right)$

$\int\left(1+csc^2t\right)^2dt$

$-1\:\cdot6$

$\lim\:_{x\to\:\:3}\frac{x^2-2x-3}{4x-12}$

$tan\left(b\right)+cot\left(b\right)=2csc\:\left(2b\right)$

$\left(\frac{d^2y}{dx^2}\right)+\frac{dy}{dx}+\left(x-2\right)y=0$