# Identify meaning of a TeX string

I'm trying to identify the meaning of some TeX symbols.

I don't work with it or anything, it just cropped up online and I was wondering if anybody could shed any light on it.

\ddot{x} + \delta \dot{x} + \alpha x + \beta x^3 = \gamma cos(\omega t)

• – Peter Grill Jun 4 '16 at 1:08
• it looks like an ordinary differential equation for an externally driven and damped oscillator – user31729 Jun 4 '16 at 6:41

Putting your example into a small TeX document (cos corrected to \cos)

\documentclass{article}
\begin{document}

$\ddot{x} + \delta \dot{x} + \alpha x + \beta x^3 = \gamma \cos(\omega t)$

\end{document}


you have

It is easy to see that \alpha, \beta and so on generate Greek letters, \dot and \ddot provide "accents" that denote the first and second derivative of the variable x with respect to time t, and \cos generates the standard abbreviation for the cosine function.

• +1. I've taken the liberty of streamlining the final paragraph a bit. – Mico Jun 4 '16 at 6:11
• There's still a word typo (correted → corrected) -- Since I hardly edit answers, I leave it to tex.stackexchange.com/users/26134/przemys%c5%82aw-scherwentke ;-) – user31729 Jun 4 '16 at 6:39
• @ChristianHupfer - Don't be too shy about using your editing rights -- you've very much earned them! :-) – Mico Jun 4 '16 at 7:36
• @Mico: I'll start immediately and edit all your lua based answers ;-) – user31729 Jun 4 '16 at 8:17
• @Mico Thank you! Now it is much better than it was in my poor English. (As poor Jane's scrofula [Look Homeward, Angel by Thomas Wolfe]). – Przemysław Scherwentke Jun 4 '16 at 10:52