Table of Contents:
$$ \frac{d}{dx}f(x) $$
$$ \frac{d}{dx}\biggr(\frac{1}{x}\biggr) = \, -\frac{1}{x^2}, \enspace x \neq0 $$
$$ \frac{d}{dx}\biggr(\frac{1}{x}\biggr) = \, -\frac{1}{x^2}. $$
$$ \frac{d}{dx}\sqrt{x}=\frac{1}{2\sqrt{x}}, \enspace x>0 $$