Plot function of two variables in 2D space

I have the function V(x1,x2) = x1^3 + x2^2

I am trying to plot k = x1^3 + x2^2 for different values of k (i.e. k=0.2, 0.4, etc.) for x1 = [0,1] and x2 = [0,1]. The plot will be limited by the x1 and x2 values that are allowable.

I am having trouble plotting this in 2D Matlab. Any help is appreciated.

The plot should look something like this:

Answer 1

[Matt J]

V = @(x1,x2)  x1.^3 + x2.^2;

fcontour(V,[0,1])