more pics

and \usepackag{pst-plot} to preamble (in that order)

I think the problem with the other entry was some spurios lank line I left in the middle of the graphic

this one shows both lines you talk about in the entry. as usual, add captions if needed

\begin{center}
\begin{pspicture*}(-4.4,-4.4)(4.2,4.4)
\psaxes[labels=none,ticks=none](0,0)(-4,-4)(4,4)
\psgrid[subgriddiv=1,griddots=10,gridlabels=7pt](-4,-4)(4,4)
\psplot[linecolor=blue,linewidth=1pt]{-1.65}{1.65}{2 sqrt 1 add x mul}
\uput[-45](1.5,3.5){$y=(1+\sqrt{2})x$}
\psplot[linecolor=red,linewidth=1pt]{-4}{4}{1 2 sqrt sub x mul}
\uput[-10](-3.8,1.8){$y=(1-\sqrt{2})x$}
\end{pspicture*}
\end{center}

Parting words from the person who closed the correction:
Status: Accepted
Reference to the user who closed the correction.:
Reference to the article this correction is about:
Status of the article (was it accepted?):
1
Status of the article (is it closed?):
1
What kind of correction is this:
Meta