suppose we have the following functions
f[x_,y_]:=Cos[x]+Cos[y];
g[x_,y_]:=x^2+y^2;
How to plot the contour formed by (x,y) points where the functions f[x,y] touches with g[x,y]? I had tried by the following command,
ContourPlot[f[x,y] ==g[x,y],{x,-Pi,Pi},{y,-Pi,Pi},PlotPoints -> 100];
But I failed.
Someone please help me how to fix it.