For $\TeX$ and $\LaTeX$ fragments I use the =texfrag= package. This allows to insert math fragments inside documents.

Example:

$$e^{ix} = cos x + i sinx$$

For $\TeX$ and $\LaTeX$ fragments I use the =texfrag= package. This allows to insert math fragments inside documents.

Example:

$$e^{ix} = cos x + i sinx$$