# $\sin{x}$ or $\mathrm{sin}\ x$

Compare:

```
\documentclass{article}
\begin{document}
\[ x\sin^{2} (t) + x\cos^{2} (t) = x\]
\[ x\mathrm{sin}^{2}\ (t) + x\mathrm{cos}^{2}\ (t) = x\]
\end{document}
```

in my opinion, the first option is much clearer.

Considering also my registration on Math.SE., any user can adopt the long notation `\operatorname{...}`

(eq. n. `(3)`

) which provides the same white spaces as the formula n. `(2)`

. `\operatorname{...}`

can be used to define any mathematical operator, with the correct spaces, when yo're using `MathJaX`

.

You can observe that the `(2)`

(it has been used `\sin`

and `\cos`

operators) and for the `(3)`

`\operatorname{...}`

and they are the same. It is visible that using `\mathrm{sin}`

with severals `\`

, you have note the correct blank spaces.

```
\documentclass[a4paper,12pt]{article}
\usepackage{amsmath,amssymb}
\usepackage{xcolor}
\begin{document}
\noindent Limited spaces for the operators:
\[\color{red}{\mathrm{sin}(\alpha+\beta)=\mathrm{sin}\alpha\mathrm{cos}\beta+\mathrm{cos}\alpha\mathrm{sin}\beta} \tag{1}\]
Correct spaces for the operators:
\[\color{green}{\sin(\alpha+\beta)=\sin\alpha\cos\beta+\cos\alpha\sin\beta} \tag{2}\]
Correct spaces for the operators: same of the previous code:
\[\color{green}{\operatorname{sin}(\alpha+\beta)=\operatorname{sin}\alpha\operatorname{cos}\beta+\operatorname{cos}\alpha\operatorname{sin}\beta} \tag{3}\]
Additional spaces given by the control \verb| \ | showing a bad spacing:
\[\color{red}{\mathrm{sin}(\alpha+\beta)=\mathrm{sin} \ \alpha \ \mathrm{cos} \ \alpha+ \mathrm{sin}\ \alpha \ \mathrm{cos} \ \alpha}\tag{4}\]
\end{document}
```