I have equations inside text.
I tried to bold equation from lyx text style->series bold
but only text is bolded but equations are not.
I can make font larger for equation and other options but bold and italic is not working for equations
[Tex/LaTex] how to bold equation in lyx
boldelsarticleequationslyx
Related Solutions
Opening the font in Font Manager it appears that the Oxford font does not have bold and italic features -- these show as being provided by the rendering library, as opposed to being provided by a font file. I would guess that LyX just fakes these features in the editor view.
As you yourself mention in a comment, fontspec (the package that handles loading of True Type and Open Type fonts) can fake these features, by adding to the preamble
\setmainfont[AutoFakeBold,AutoFakeSlant]{Oxford}
Note that you have to use the XeTeX engine for this to work (at least the fake bold), so use View --> View (Other formats) --> PDF (XeTeX), and the equivalent for updating. This does not work with the LuaTeX engine.
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.
\documentclass{article}
\usepackage{bm}
\begin{document}
\begin{equation}
\bm{F} = k\bm{x}
\end{equation}
\end{document}
Best Answer
You have to use the specific font options for math mode. Select the text in the math mode box and use this button on the math toolbar: