$\frac{3x^3+5x}{x^2+1}$

$\int\left(e^{-2x}\cos\left(3x\right)\right)dx$

$\lim_{x\to0}\left(\frac{sin\:x-sin\:\pi}{x-\pi}\right)$

$458,12\:x\:256,45$

$\frac{d}{dx}\left(\tan\left(4x-5\right)\right)$

$\left(x+3\right)^2=\left(x+2\right)^2-5$

$\lim_{x\to-2}\left(\frac{x^2-5}{x^2+4x+4}\right)$