$(1$ point$)$

Match the functions with the graphs labeled A $-$ G$.$ As always, you may click on the thumbnail image to produce a larger image in a new window $($sometimes exactly on top of the old one$).$ Just take your time; process of elimination will help with ones that are not obvious.

$f(x,y)=(x-y{)}^2$

$f(x,y)=(x^2-y^2{)}^2$

$f(x,y)=\frac{1}{1+x^2+y^2}$

$f(x,y)=3-x^2-y^2$

$f(x,y)=sin(x)sin(y)e^{-x^2-y^2}$

$f(x,y)=sin(y)$

$f(x,y)=cos\frac{x^2+y^2}{1+x^2+y^2}$