Did you know you can write mathematics in comments and posts here?  It’s easy.  (You can also typset your assignments beautifully in LaTeX -- more info on that under Resources.)

To add an equation to a comment or post, you surround your math with at the beginning and at the end. So, you write

YOUR MATH HERE

You can use symbols like + x – and for exponents you can write ^.  For subscripts you can use _.  So for example,

x^2y_3+6=z_2^7

produces

You can also write fractions this way:

\frac{a}{b}

producing

You can make an integral like this:

2\pi \int_a^b f(x) dx

producing

You can make a sum, and limits, like this:

\lim_{N \rightarrow \infty} \sum_{i=1}^{N} \frac{1}{i} = \infty

producing

Here's a real pro tip: if you put an exclamation mark after the first two dollar signs, it works harder to make things pretty, and always puts them centred on a separate line. So for example,

\lim_{N \rightarrow \infty} \sum_{i=1}^{N} \frac{1}{i} = \infty

produces

Finally, you can make a matrix this way:

\begin{pmatrix} 1 & 2 & 3 \\ 4 & 5 & 6 \\ 7 & 8 & 9 \end{pmatrix}

and you’ll get

If you have a symbol in mind and want to know the latex for it, draw it in the "deTexifyer":

http://detexify.kirelabs.org/classify.html

For a browsable list of lots of math symbols you can use, see

http://www.maths.tcd.ie/~dwilkins/LaTeXPrimer/MathSymb.html

Feel free to use the comments here for testing.