# Bolding text generated by physics package

I would like to point out that you can change the font of `\partial`

and `d`

with the derivative package using the option `style-inf=<font>`

```
\documentclass{article}
\usepackage{amsmath}
\usepackage{bm} % pdflatex
%\usepackage{unicode-math} % lualatex or xelatex
\usepackage{derivative}
\derivset{\pdv}[style-inf=\bm] % pdflatex
\derivset{\odv}[style-inf=\bm] % pdflatex
%\derivset{\pdv}[style-inf=\symbf] % lualatex or xelatex
%\derivset{\odv}[style-inf=\symbf] % lualatex or xelatex
\begin{document}
\begin{equation}
\pdv{ f(x,y,z) }{ x, y, z } \quad \odv{ f(x) }{ x }
\end{equation}
\end{document}
```

If you want upright bold `d`

, then you should use `\RenewOdvVariant{\odv}{\bm{\mathrm{d}}}`

with pdflatex instead of `\derivvset`

, because `\derivset{\odv}[style-inf=\bm\mathrm]`

will throw an error.

The `diffcoeff`

package also allows the easy use of a bold `\partial`

or `d`

. You will need names for them, say `ob`

for ordinary-derivative-bold, and `pb`

for partial-derivative-bold:

```
\documentclass{article}
\usepackage{bm}
\usepackage{diffcoeff}
\diffdef{ob}{ op-symbol = \bm{ \mathrm{d}} }
\diffdef{pb}{ op-symbol = \bm{\partial} }
\begin{document}
\[
\diff.ob.{\mathcal{Q}(\bm{\tau})}{\tau_{t}}\qquad
\diff.pb.{\mathcal{Q}(\bm{\tau})}{\tau_{t}}
\]
\end{document}
```

If you don't want to write `\diff.ob.`

and `\diff.pb.`

all the time, follow the `\diffdef`

commands in the preamble with

```
\newcommand{\ob}{\diff.ob.}
\newcommand{\pb}{\diff.pb.}
```

or some other names of your choosing. You can then replace the `\diff.ob.`

with `\ob`

and `\diff.pb.`

with `\pb`

.

I will use the classic `\frac`

instead of the packages `physics`

, `diffcoeff`

, `derivative`

.

```
\documentclass[a4paper,12pt]{beamer}
\usepackage{mathtools,amssymb}
\usepackage{bm}
\begin{document}
\[
\mathcal{Q}(\bm{\tau})=\frac{{\bm\partial}z^*(w)}{{\bm\partial}\tau_t}\frac{{\bm d}x}{{\bm d}t}
\]
\end{document}
```