# Bracket extending on two lines

I need to write something like this in latex:

I can use \Big\{ or \bigg\{, but the problem is that all I write next goes on a single line. I need to embed the bracket into two lines, how to do that in latex?

• Please add your MWE (your current code) to the post, it will help us to start working on it. – Malipivo Apr 3 '14 at 11:18
• The common solution to this looks something like this: \left\{ \begin{array}{ccc} ... \end{array} \right. ... – Malipivo Apr 3 '14 at 11:19

use mathtools, which is an extended amsmath and also \left...\right:
\documentclass{article}
$C_2 = \begin{cases} 0.45 \times \dfrac{\sigma^2}{\sigma^2+0.09} \times \sin \alpha & \text{if \gamma \geq 0} \\[4pt] 0.45 \times \dfrac{\sigma^2}{\sigma^2+0.09} \times \left(\sin \alpha - \left(\dfrac{2 \beta}{\pi}\right)^3\right) & \text{otherwise} \end{cases}$

• cases just requires amsmath; it's dcases that requires mathtools; within dcases \dfrac can be \frac and the vertical spacing is improved. – egreg Apr 3 '14 at 12:01
• It ia always a good idea to load mathtools instead of amsmath ... – user2478 Apr 3 '14 at 13:23