$\frac{d}{dx}2^x$

$\frac{-18x^5}{5x^7}\cdot\frac{-25x}{9x^3}$

$\frac{dy}{dx}=\frac{x^3+x}{4y^3}$

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

$\lim_{x\to3}\left(\frac{2x^2-5x-3}{x-3}\right)$

$x-\sqrt{x-1}=3$

$\lim_{n\to\infty}\left(\frac{2\sqrt{3}}{n^2+n}\right)$