Min and max in integral

I want to solve the following integral: z = 15; syms x1 x2 x3 x4 f f = ( x1 + x2 + x3 + max(0,x3-x4) )*(exp(-lambda*x4)*power(lambda,Q)); result = int(int(int(int(f,'x1',0,x2),'x2',0,x3),'x3',0,x4),'x4',0,z);

But i have this error: Undefined function 'max' for input arguments of type 'sym'.

Could you please help me...

Answer 1

[Massimo Zanetti]

To get max of symbolic variables x,y try this:

max(double([x,y]))

[saeed poormoaied]

Hi Zanetti,

Unfortunately, It does not work. I copy a simple code here:

clear all close all clc

lambda = 11; Q = 4; z = 15; L = 10; r = 1;

syms x1 x2 x3 x4 f = ( x1 + x2 + x3 + max(double([0,x3-x4])) )*(exp(-lambda*x4)*power(lambda,Q)); result = int(int(int(int(f,'x1',0,x2),'x2',0,x3),'x3',0,x4),'x4',0,z);