# Missing \$ inserted although I have \$ [closed]

I get "Missing \$ Inserted" when typing in this:

``````Genom att undersöka var kurvan \${f_{A}(x)}\$ skär linjen T = 20 ser vi att x ≈ 4,3 då \${f_{A}(x)}\$ = 20.\\
``````

Where is my fault?

• Is that a unicode approx between `x` and `4,3`? Try substituting for \$x\approx 4,3\$ and see if it helps. May 12, 2013 at 19:38
• There is no missing `\$` here. However you should be typing `kurvan \$f_{A}(x)\$ skär linjen \$T=20\$ ser vi att \$x\approx 4{,}3\$ då \$f_{A}(x) = 20\$.` (And no `\\`, to end a paragraph use a blank line.) May 12, 2013 at 19:39
• @egreg well there is due to the strange inputenc design (sorry for that) that some characters end up automatically being math chars so the \approx as a unicode char triggers mathmode (most likely) ... but of course you are right that it should have been written with several formulas in the first place May 13, 2013 at 20:06

The missing `\$` is probably caused by `≈`. While it may be convenient to use direct Unicode input, not all symbols are defined, so you may incur in problems.

For instance, there's no definition for `≈` with the `utf8` option for `inputenc`, while there is (as a math symbol) with the `utf8x` option (that I don't recommend).

``````Genom att undersöka var kurvan \$f_{A}(x)\$ skär linjen \$T = 20\$
Note that `T=20` is a math formula and that commas used for separating the decimal part must be enclosed in braces (or a package such as `icomma` should be used).
Don't use `\\` to end paragraphs, just leave a blank line in the input.