http://www.forkosh.com/mimetextutorial.html
Use the [ tex ] bbc code (
)
[tex]\left(\frac1{1-x^2}\right)^2[/tex]
gives you this: [tex]\left(\frac1{1-x^2}\right)^2[/tex]
[tex]\Large A\ =\ \large\left(\begin{array}{c.cccc}&1&2&\cdots&n\ \hdash1&a_{11}&a_{12}&\cdots&a_{1n}\ 2&a_{21}&a_{22}&\cdots&a_{2n}\ \vdots&\vdots&\vdots&\ddots&\vdots\ n&a_{n1}&a_{n2}&\cdots&a_{nn}\end{array}\right)[/tex]
[tex]a+b/2[/tex]