$\lim_{x\to\infty}\frac{\cos x}{\tan x}$

$\frac{4^3\:x\:\left(4^2\right)^5\:x\:4^6}{4^4\:x\:4\:x\:\left(4^2\right)^5}$

$\frac{1-cos^2x+sin2x-sin^2x}{1+cos2x}=\tan\left(x\right)$

$\lim_{x\to-1}\frac{\left(x\left|x+1\right|\right)}{x+1}$

$45.07-3.005$

$\frac{dy}{dx}=-\frac{-0.5}{\cos\left(y\right)}$

$\lim_{x\to\infty}\left(\sqrt{x^3+4x}\right)$