Help:Mathematics

Math is handled by the LaTeX typesetting system
Don’t use equation numbers
Indent block equations with a colon (see examples below)
Mediawiki will render HTML characters for short equations, and PNG images for longer ones
To force image rendering, add a space at the end of the equation with a solidus (backslash) followed by a space

Examples

Example short equation: $E=mc^{2}$

Example short equation with forced image rendering, using a space at the end of the equation:

E=mc^{2}\

Longer equations render as images regardless; here's the Aki-Richards equation:

R_{\mathrm {PP} }(\theta )={(1+\tan ^{2}\theta )\,{\frac {\Delta I_{\mathrm {P} }}{2I_{\mathrm {P} }}}}\ \ -\ \ {8\left({\frac {V_{\mathrm {S} }}{V_{\mathrm {P} }}}\right)^{2}\sin ^{2}\theta \,{\frac {\Delta I_{\mathrm {S} }}{2I_{\mathrm {S} }}}}\ \ -\ \ {\left[{\frac {1}{2}}\tan ^{2}\theta -2\left({\frac {V_{\mathrm {S} }}{V_{\mathrm {P} }}}\right)^{2}\sin ^{2}\theta \right]{\frac {\Delta \rho }{\rho }}}

Constants and names or label are roman (i.e. upright, not italic): V_P. Use \mathrm{P} in LaTeX math.
Pi, e, the differential d, and lots of other symbols are usually roman
Variables are italic (the default character style in LaTeX math)
Vectors are roman and bold (use \mathbf{} — it's best to avoid \vec{}, which uses the arrow notation)
Use the built-in LaTeX functions for \sin, \log, etc.