# Why does inline math require \ before $? I just asked this question, but my inline math didn't work until I put a backslash before the dollar signs $like so$. Why is the backslash required? That isn't the case on other sites. • I came here to ask if it's just me, and found it was already asked. I confirm the issue, and added a screenshot to illustrate the issue. Jun 1, 2020 at 8:15 ## 2 Answers Sometimes, when MathJax is added to a site when it's mature and has a lot of posts already, Stack Exchange staff chooses to use $delimiters instead of . This is to prevent things like There are a few decent options in the 10-20 range. being displayed as There are a few decent options in the $$\10-\$$20 range. There are a handful of other sites in the network where this the case: for a complete list, see Which Stack Exchange sites use MathJax?. • That's cool. Thanks. Out of interest, how would one write 10-20 in sites which do not use$? Jun 1, 2020 at 9:30 • Surprise, surprise (I didn't know it either, I just tried): that's possible by using $. Jun 1, 2020 at 9:32 • haha, nice, thankyou Jun 1, 2020 at 9:50 Because when we added MathJax to the site, Stack Exchange staff decided to use$ as delimiters rather than$ because many posts would be impacted otherwise. They cite an analysis by one of our citizens:

There are 349 posts that contain dollar signs, more than twice my estimate for posts that might benefit from MathJax (162). 137 of the 349 contain 2 dollar signs, if that matters.

— Miniman Nov 12 '15 at 0:37

You can see the original post requesting MJ on RPG here, and the post announcing its going live here.

(I know this doesn't really add much to Glorfindel's answer—really I just wanted to link both of those posts into this conversation, and my conscience wouldn't let me leave them in comments that really do answer the question.)

• Thanks for sharing that info! I think the answer does add something :)
– V2Blast StaffMod
Jun 1, 2020 at 20:20