I try to plot the function f(x,y)=(100-(x^2*y^2))^0.5 in Matlab using

x = 0:0.1:10;
y = 0:0.1:5;
[X,Y] = meshgrid(x,y)                            
Z = (100-(X.^2.*Y.^2)).^(0.5)
surf(X,Y,Z) 

I managed to do so with the following online-plotter:

x = 0:0.1:10;
y = 0:0.1:5;
[X,Y] = meshgrid(x,y);                            
Z = real((100-(X.^2.*Y.^2)).^(0.5));
surf(X,Y,Z);