$f\left(x\right)=3x^2+8x^{-5}+5x^{-3}$

$\frac{1}{\cos\left(x\right)}-\cos\left(x\right)\sin\left(x\:-\:y\right)$

$\frac{x^3+7x^2+11x-3}{x+3}$

$4x^4-4x$

$\log_{12}\left(2x\right)+\log_{12}\left(x-1\right)=1$

$\lim_{x\to\infty}\left(\frac{ln\left(x-1\right)}{ln\left(x-1\right)}\right)^x$

$2\sec\left(x\right)^{2\:}=3\:\tan\left(x\right)^2\:+1$