a=[1,2];
b=[2,3];
c=[1,4];
% Getting all the combinations
[x1,x2,x3]=ndgrid(a,b,c);
% reshaping them as a column vector;
x1=x1(:);
x2=x2(:);
x3=x3(:);
disp([x1 x2 x3])
1 2 1
2 2 1
1 3 1
2 3 1
1 2 4
2 2 4
1 3 4
2 3 4
% Calculating F as instructed.
F = x1.*(x2-x3)
F =
1
2
2
4
-2
-4
-1
-2
