Indent 2nd line of an item in description environment

Question

I have some equations that span multiple lines. In the document, I have the following description environment:

\begin{description}
\item[(F1)]
$First Line \\$, 
$Second Line \\$
$Third Line $
\end{description}

The effect that I am trying to achieve, is to indent the second line and third line as follows, but it does not work:

\begin{description}
\item[(F1)]
$First Line \\$, 
\quad $Second Line \\$
\quad\quad $Third Line $
\end{description}

I have tried using \quad inside and outside the $$, but failed. Any advice is greatly appreciated.

P.S. The solutions suggested in How to indent second line of an item enumerate are not what I need. Also, I am not able to change any formatting commands. I need to do this simply by using something like \quad, \hspace.

Answer 1

Use \hspace*, and write \\ outside mathmode:

\begin{description}
\item[(F1)]
$First Line $,\\
\hspace*{1em}$Second Line$ \\
\hspace*{2em}$Third Line $
\end{description}

Answer 2

Why not define each line as a paragraph instead of breaking the line with \\ ? This allows for \quad to work. Also you can use \qquad for double quad.

my suggestion:

\begin{description}
    \item[(F1)]
    $First Line $,

    \quad $Second Line$

    \qquad $Third Line $
\end{description}