How can i plot this 3D function?

Hi, im trying to plot

f(x,y)= e^(x-y) +x^2 +y^2

but in every way i try to plot it it returns the wrong graph (it should be a paraboloid). This is the code im using:

[X,Y]= meshgrid(-10:10);
Z= exp(X-Y) + X.^2 + Y.^2;
surf(X,Y,Z)

Thank you for your help!

Answer 1

[Ameer Hamza]

Paraboloid is Z = X.^2 + Y.^2;

[X,Y]= meshgrid(-10:10);
Z = X.^2 + Y.^2;
surf(X,Y,Z)

Due to exp() term in your equation, you won't necessarily get a paraboloid.

[Francesco Bellora]

mhh, sorry if i didn't explained myself very well; i tried to plot this function with geogebra or wolfram, and both of them returned to me a paraboloid-like graph; i instead keep getting this:

I don't know if the problem is in the syntax of the code or the funcion, or if its only a problem of scaling...

ty anyway for the quick response

[Ameer Hamza]

Yes, the graph generated by GeoGebra has a very small range of z-axis. The following code changes the range.

[X,Y]= meshgrid(linspace(-2,2));
Z = exp(X-Y) + X.^2 + Y.^2;
surf(X,Y,Z)
xlim([-5 5])
ylim([-5 5])
zlim([-1 7])
shading interp

[Francesco Bellora]

Thanks!