MATLAB: How does one use integral2 (double integral) symbolically

Question

I would like to get some help on how to use the integral2 symbolically?

E.g. I have a Joint PDF function -> "@(x,y) exp(-(x+y))"

To verify that it adds up to one, I did the following -> "integral2(pdf,0,inf,0,inf)" with the result being 1 as expected.

Now to calculate the Joint CDF symbolically I defined x and y as symbols and tried to do -> "cdf=@(u,v) exp(-(u+v))" and "integral2(cdf,0,x,0,y)". The error I got was -> "Error using integral2. XMAX must be a floating point scalar."

What I want to get is -> "(1-exp(-y))*(1-exp(-x))" !!

Your help will be much appreciated.

Answer 1

From the documentation of integral2:

integral2
Numerically evaluate double integral

http://www.mathworks.com/help/matlab/ref/integral2.html

It is not meant for symbolic computation. If you are interested in symbolic results you need to have Symbolic Toolbox installed

Then you can use the int function:

http://www.mathworks.com/help/symbolic/int.html