[tex]x= \frac{4}{\sqrt{2}-1 } \\
x= \frac{4( \sqrt{2}+1) }{2-1} \\
x=4( \sqrt{2}+1)
[/tex]
[tex]y= \sqrt{(1- \sqrt{2})^{2} } \\
y=| 1- \sqrt{2} | \\
y= \sqrt{2}-1 [/tex]
[tex]mg= \sqrt{x*y} \\
mg= \sqrt{4( \sqrt{2}+1)( \sqrt{2}-1) } \\
mg= \sqrt{4(2-1)} \\
mg= \sqrt{4}=2 [/tex]