formula test

Here’s an example of the quadratic formula:
$x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}$

And the Riemann zeta function:
$\zeta(s) = \sum_{n=1}^\infty \frac{1}{n^s} = \frac{1}{1^s} + \frac{1}{2^s} + \frac{1}{3^s} + \cdots$