How to make a vector bold and italic inside an equation

Question

I want all my equations to be in italics and the vectors to be bold as well. When I write the following LaTeX code it gives italic equations:

\begin{equation}
F = kx
\end{equation}

But when I re-write to make the vectors bold, the vectors become bold but don't stay italic anymore:

\begin{equation}
\mathbf{F} = k\mathbf{x}
\end{equation}

How can I keep the whole equation in italics with vectors appearing as bold?

score 15 · Answer 1 · answered Oct 27 '13 at 00:59

You could use the bm package and its command \bm. One of the very nice things about this package is that \bm works equally well on letters and symbols; thus, one doesn't have to remember to use \mathbf on letters and \boldsymbol on symbols. Another nice aspect -- especially useful for your setup -- is that you get bold-italic rather than bold-upright output.

enter image description here

\documentclass{article}
\usepackage{bm}
\begin{document}
\begin{equation}
\bm{F} = k\bm{x}
\end{equation}
\end{document}

score 5 · Answer 2 · answered Oct 27 '13 at 00:18

5

\documentclass[preview,border=12pt]{standalone}
\usepackage{amsmath}
\begin{document}
\abovedisplayskip=0pt\relax%don't use this line in your production
\begin{equation}
\boldsymbol{F} = k\, \boldsymbol{x}
\end{equation}
\end{document}

enter image description here

answered Oct 27 '13 at 00:18

kiss my armpit

36,086

a clean solution. Why to use this rare extra package bm when the amsmath package is so common? :) – loved.by.Jesus Apr 10 '17 at 13:29

score 1 · Answer 3 · edited Apr 13 '17 at 12:35

1

You can also use the \bm command, from the bm package, which seems preferable in a number of cases. See: \bm package versus \boldsymbol

edited Apr 13 '17 at 12:35

Community

1

answered Oct 27 '13 at 00:56

Bernard

271,350

How to make a vector bold and italic inside an equation

3 Answers3