$\lim_{x\to0}\left(\frac{sin\left(2x\right)}{5sec^2\left(5x\right)}\right)$

$6x^5-9x^3+8-x^5-3x^{-3}+6$

$\lim_{x\to\infty}\left(\frac{x^{10}}{e^{10x}}\right)$

$x^3y^{-1}\cdot x^{-4}y^2$

$\sec^20=1+\sin^20\sec^20$

$\frac{dy}{dx}=\frac{9x^2}{3y^2-6}\:$

$\left(3x-5y\right)\left(8y-9x\right)$