Take the 2-minute tour ×
Mathematics Stack Exchange is a question and answer site for people studying math at any level and professionals in related fields. It's 100% free, no registration required.


I want to calculate above integral in Maple, the parameters $n_1,n_2,n_3$ are all natural numbers.

I execute the following command:

int(int((1-x)**(1-y)*(x+y)*(x^n_1)*(y^n_2)*(1-x-y)^n_3, y=0..1-x),x=0..1); 

After I pressed enter the following error message appeared:

"Error, unable to match delimiters"

I'm new to Maple, could any one tell me what the problem here is and which would be the correct command? I think I can learn the commands for computing a range of integrals like this once I know the correct command for this integral.

share|improve this question

closed as off topic by Marvis, user26872, LVK, sdcvvc, William Sep 2 '12 at 6:21

Questions on Mathematics Stack Exchange are expected to relate to math within the scope defined by the community. Consider editing the question or leaving comments for improvement if you believe the question can be reworded to fit within the scope. Read more about reopening questions here. If this question can be reworded to fit the rules in the help center, please edit the question.

You may also want to ask your question here: mathematica.stackexchange.com/questions –  math-visitor Jul 10 '12 at 8:16
What version. Your command worked fine for me. –  martini Jul 10 '12 at 10:21
My version is Maple 15 –  user31899 Jul 10 '12 at 11:35

1 Answer 1

up vote 0 down vote accepted

Be careful about the syntax for multiplication. Above your expressions contains,


which is the syntax for powering. Eg, 3**4 evaluates to 81.

Another pitfall of multiplication syntax is to omit a multiplication sign (explicit multiplication) or an appropriately placed space (, for implicit multiplication in 2D Math entry mode). Eg, (1-x)(1-y) would get interpreted as function application.

It's not clear whether you have proper values for n_1, n_2, and n_3. If they are not actual numbers then you may have to place some assumptions (if you know any) on them in order for Maple to get a purely symbolic result. For example, the following leads to symbolic result a few pages long,

int(int( expand( (1-x)*(1-y)*(x+y)*(x^n_1)*(y^n_2)*(1-x-y)^n_3 ),
         y=0..1-x), x=0..1)
            assuming n_1::posint, n_2::posint, n_3::posint; 

You could use nonnegint there instead, if you meant to allow n_1=0, etc.

share|improve this answer

Not the answer you're looking for? Browse other questions tagged or ask your own question.