How to integrate the following function(using "int" command)

How to integrate the following function(using "int" command)

f(x)=

   x      if 0 < x < 2
   x^2    if 2 <= x <= 10

Answer 1

[Shashank Prasanna]

Why don't you set up two different integration problems:

f1 = quad(@(x)x,0,2)

f2 = quad(@(x)x^2,2,10)

If you are concerned about boundary problems, you could always perturb the values a bit.

[Shashank Prasanna]

If you are using symbolic toolbox then:

numeric::int(x, x = 0..2)

numeric::int(x^2, x = 2..10)

[Walter Roberson]

Note: numeric::int is a MuPAD function that has no MATLAB interface. You would need to use feval() or evalin() to access it.

[Shashank Prasanna]

Good point walter, I assumed Abhishek was using MuPAD from his question about 'int', hence I added the second comment. Abhisek, you can launch mupad as below if you want to work in that environment:

>> mupad
or use evalin in MATLAB as below.
>> evalin(symengine,'numeric::int(x^2, x = 2..10)')

hth

[Walter Roberson]

int() is one of the MuPAD routines that does have a MATLAB interface.

Answer 2

[Walter Roberson]

Within MuPAD you can use piecewise to define the function, and then int() it. Note that piecewise is a MuPAD function that has not MATLAB interface. You would need to use feval() or evalin() to access it.