## Double Integration Matlab

Hello

I've been trying to write an m file that can carry out double integration and plot it in 3d form, obviously I am stuck otherwise I wouldn't be posting here:

$\displaystyle (x^2y - 2xy + xy^2)dxdy$
The outer integral limits are 0 and 3, and the inner limits are 1 and 2.

So far I have this:
[FONT=Courier New]
Originally Posted by matlab
[% Function f(x) is defined by
f(x,y)=x.^2*y-2*x*y+x*y.^2;
% We are integrating this with respect to x and y
% Using the Internd funcition to evaluate this integral
f(x,y) = integrnd(x,y);
f(x,y) = x.^2*y -2*x*y +x*y.^2;
% xmin is the Lower Limit of Inner Integral
% xmax is the Upper Limit of Inner Integral
% ymin is the Lower Limit of Outer Integral
% ymax is the Upper Limit of Outer Integral
xmin = 1;
xmax = 2;
ymin = 0;
ymax = 3;
% This is integrating the function with respect to x and y
% To plot in 3d, we must use the plot3d command
plot3(x,y,z)
grid
on
title('f(x,y) represented in 3D view')
xlabel(
'x = cos(a)')
ylabel(
'y = sin(a)')
zlabel(
'z = a')

I am unsure as what to put in as x and y at the end, and also with the z=a ..

Any help is appreciated