# Creating bold and non-italic equations

I am trying to write an equation in bold and non italic but I can't get it to work because I also want to write a D with two dots over it. Here is my code:

$$\text{\boldsymbol{{M} \ddot{D}} + KD = F}.$$


Thank you!

• What do you mean by non cursive? Do you want to write all your math in non-italic? If so, you could find a way to do that by following this question and its answers. Commented Jul 25, 2021 at 9:37
• I have multiply equations but this is the only equation that I want non-italic. Commented Jul 25, 2021 at 9:42
• Try $$\mathbf{M \ddot{D}} + KD = F.$$ Commented Jul 25, 2021 at 9:44
• \mathbf{M}\ddot{\mathbf{D}} Commented Jul 25, 2021 at 9:47
• Thank you! It worked now Commented Jul 25, 2021 at 10:07

Let me spell out @egreg and my comments:

\documentclass{article}
\usepackage{mathtools}

\begin{document}
@egreg proposition:
$$\mathbf{M}\ddot{\mathbf{D}} + KD = F.$$

My proposition:
$$\mathbf{M \ddot{D}} + KD = F.$$
\end{document}


First of all, there should be no \text: you want a math formula.

If you use \boldsymbol, you get bold (math) italic. If you want bold (math) upright, the command is \mathbf.

Also, each letter should be specified with a distinct call of \mathbf and the double dot (second derivative in Newton notation) should not be bold.

Hence

\documentclass{article}
\usepackage{amsmath}

\begin{document}

$$\mathbf{M} \ddot{\mathbf{D}} + KD = F$$

\end{document}


The formula is not at all clear, though, but you know better.