"$" ("$$" to be exact) is actually used in TeX to indicate opening and closing o...

pflats · on Dec 20, 2016

>"$" ("$$" to be exact) is actually used in TeX to indicate opening and closing of statements/mathematical expressions.

Both are used. A single $ is used for inline math, the double $$ begins an equation on its own line. For example:

The solution to $ax^2 + bx + c = 0$ will be $$x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}$$

The first block will be mid-sentence, while the second one will get its own line.

widdma · on Dec 20, 2016

The story is that Knuth chose '$' to denote math mode because math typesetting at the time was prohibitively expensive.

stuffedBelly · on Dec 20, 2016

ahaha, that's a good piece of anecdote.

wangchow · on Dec 20, 2016

Ah, wasn't aware of that. Thanks. :)