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Re: problems integrating a function
Posted:
Jan 5, 2011 10:46 AM


On 04/01/11 7:29 PM, Marcio Barbalho wrote: > Please, > Could any of you find the numerical solution to the integral of > sin[(xpi)/sqrt(x)] from pi/100 to pi? > > S = int(sin((xpi)/sqrt(x)),x=pi/100..pi)
I can't speak about MuPad (the current Matlab symbolic engine), but when I investigate in Maple, I find that some of the avenues to creating the integral involve (either implicitly or explicitly) summations of an expression from 0 to infinity, and that depending on how the terms of that expression are arranged, the closed form summation may have a singularity at 0 because of a denominator term that works out as sin(Pi/2 + Pi*A) where A is the lower bound on the summation; with A being 0, that's going to give you a 0 in the denominator.
Other paths to finding the integral look like they might be fine (or at least not involving a division by 0).
I think the division by 0 that Maple comes up with in some cases is probably a bug in Maple; when I wake up more, I will write it up as a bug report for them.
Again, I have no information as to how MuPad would attempt the same calculation.



