Is there a circle symbol?

Question

Is there a circle symbol for the composition of two functions? Or do I have to resort to using other ways to represent that?

just as a tip, Wikipedia uses LaTeX style markup for their functions. When your press the edit button you can see :<math>(f\circ f)(x) = f(f(x)) = f^2(x)</math> ;) — Davy Landman, Jan 05 '11 at 08:43
Just for reference, there is also a filled circle in math mode: $\bullet$ . — Christian Herenz, Aug 31 '18 at 14:00
Thanks @ChristianHerenz! The filled circle was exactly what I was looking for. — paldepind, Sep 09 '18 at 13:15

score 207 · Accepted Answer · edited Sep 15 '21 at 05:31

207

It's \circ:

\documentclass{article}
\begin{document}
\( f \circ f \)
\end{document}

edited Sep 15 '21 at 05:31

Community

answered Jan 05 '11 at 08:19

Joseph Wright

score 84 · Answer 2 · edited Jan 05 '11 at 10:16

84

Probably this is a good chance to recall the Detexify website, where you can simply draw the symbol you want, and obtain the needed code.

I'm a bad illustrator, but for me, after drawing the circle, \circ was the first hit.

edited Jan 05 '11 at 10:16

Andrew Stacey

answered Jan 05 '11 at 10:05

Dror

8

I'd like to add that I tried to find this symbol with detexify but I failed as I found many other similar looking symbols but not \circ. I actually needed to google "latex combine function symbol", to find this question. – ohcibi May 15 '16 at 17:40
5

Would be great if detexify could use context, so you could draw f o g. – OJFord Feb 26 '17 at 04:27

2 Answers2