Let's consider $a\ne 0$. Maths between dollars is inline: \(\sum_{k=1}^n k = \frac{n(n+1)}{2}\). Maths between slash-square-brackets is display: \[\sum_{k=1}^n k = \frac{n(n+1)}{2}\] Einstein's most famous equation is \(E=mc^2\). Newton derived the equation [s=ut+\sfrac{1}{2}at^2] \[s=ut+\frac{1}{2}at^2\]

E=mc^2

E=mc^2

$$E=mc^2$$ \[s=ut+\frac{1}{2}at^\] $$\forall x \in X, \quad \exists y \leq \epsilon$$ $$\alpha, \Alpha, \beta, \Beta, \gamma, \Gamma, \pi, \Pi, \phi, \varphi, \Phi$$ $$\frac{n!}{k!(n-k)!} = \binom{n}{k}$$ $$\begin{equation} x = a_0 + \cfrac{1}{a_1 + \cfrac{1}{a_2 + \cfrac{1}{a_3 + \cfrac{1}{a_4} } } }\end{equation}$$ $$ A_{m,n} = \begin{pmatrix} a_{1,1} & a_{1,2} & \cdots & a_{1,n} \\ a_{2,1} & a_{2,2} & \cdots & a_{2,n} \\ \vdots & \vdots & \ddots & \vdots \\ a_{m,1} & a_{m,2} & \cdots & a_{m,n} \end{pmatrix} $$ \[ f(n) = \left\{ \begin{array}{l l} n/2 & \quad \text{if $n$ is even}\\ -(n+1)/2 & \quad \text{if $n$ is odd} \end{array} \right.\] \[ f(n) = \left\{ \begin{array}{l l} n/2 & \quad \text{if $n$ is even}\\ -(n+1)/2 & \quad \text{if $n$ is odd} \end{array} \right.\]