# Not able to show negative signs

I have the following.

\item Arrange in ascending order (smallest to largest): $−6, −2, 0, 1, −5, 4, 3$


But this output does not have negative signs.

6, 2, 0, 1, 5, 4, 3


It shows negative in other places.

\item Evaluate $(-2)^2$


This output has a negative sign.

Evaluate (−2)2

What am I doing wrong here?

Thank you in advance.

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The minus signs in $−6, −2, 0, 1, −5, 4, 3$ are not hyphens - (0x2d) but dashes − (0x2212). A dash is slightly longer than a hyphen.

Solution: Replace dashes with hyphens.

The minus sign in \item Evaluate $(-2)^2$ is already a hyphen.

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Note that \usepackage{lmodern} is extremely illuminating in this respect! – cfr Apr 11 '14 at 3:03
Thanks. It happened so because I copy and paste it from MS Word. – shin Apr 11 '14 at 3:05
@shin That warning is good to know, re: MS Word. – Steven B. Segletes Apr 11 '14 at 3:47
The advice is correct but note that U+2212 isn't a "dash" it is "MINUS SIGN" so typographically it's the correct character, so in unicode-math it should work, but for classic tex, as you say you should use - just as you should use  and ' rather than typographical left and right qutes as TeX input. – David Carlisle Apr 11 '14 at 6:52

If you're doing much copy-paste from word processors, then it's better to load

\usepackage[utf8]{inputenc}


in your LaTeX document. Then you can teach LaTeX new correspondences between Unicode characters and LaTeX set of known objects, in this case

\documentclass{article}
\usepackage[utf8]{inputenc}
\usepackage{newunicodechar}

%% the first is the “unknown minus” (U+2212), the second is a hyphen
\newunicodechar{−}{-}

\begin{document}
$−1$
\end{document}


How do you know there's something amiss? Look in the .log file: you should find several instances of something like

Missing character: There is no <E2> in font cmr10!
Missing character: There is no <88> in font cmr10!
Missing character: There is no <92> in font cmr10!


one for each “disappearing” minus sign. Indeed, if you don't load inputenc with the utf8 option, TeX just sees the three byte representation of U+2212, precisely the bytes 0xE2, 0x88 and 0x92 that don't correspond to a printable character, because the default TeX fonts have only 128 glyphs.

With utf8, but no \newunicodechar declaration you'd get an error:

! Package inputenc Error: Unicode char \u8:− not set up for use with LaTeX.


and you can so understand what went wrong: the minus sign is not understood. Copy it and use it for defining the correct \newunicodechar` declaration.

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