How to add argmin and argmax to LyX

To use argmin and argmax in LyX (or LaTeX in general), simply add the following three lines in the LaTeX preample from Document -> Settings as show below:

\usepackage{amsmath} 
\DeclareMathOperator*{\argmin}{argmin}
\DeclareMathOperator*{\argmax}{argmax}

and then use it in any equation as \argmin or \argmax.

References

• http://www.briandalessandro.com/blog/how-to-add-the-arg-max-and-arg-min-functions-to-lyx/
• http://tex.stackexchange.com/questions/5223/command-for-argmin-or-argmax