Test

$a^2 + b^2 = c^2$

\begin{align*} e^x & = 1 + x + \frac{x^2}{2} + \frac{x^3}{6} + \cdots \\ & = \sum_{n\geq 0} \frac{x^n}{n!} \end{align*}

KaTeX is faster to render then MathJax, but does not support stuff like \begin{align*}

$$ e^x = 1 + x + \frac{x^2}{2} + \frac{x^3}{6} + \cdots = \sum_{n \geq 0} \frac{x^n}{n!} $$

Typeset mathematics contained inline (within) with the text of a paragraph needs to take less space than the same math typeset outside the paragraph text as standalone, display-style, material. To see this in practice, let’s explain that the equation $f(x) = \sum_{i=0}^{n} \frac{a_i}{1+x}$ may diverge or converge depending on the value of $x$. We can also typeset $f(x)$ outside the paragraph in display style:

$$f(x) = \sum_{i=0}^{n} \frac{a_i}{1+x}$$

LaTeX code with TikZ should be placed inside <tikzjax></tikzjax>