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Integrate bug

  • To: mathgroup at smc.vnet.net
  • Subject: [mg108232] Integrate bug
  • From: Daniel <daniel.ernesto.acuna at gmail.com>
  • Date: Thu, 11 Mar 2010 06:36:27 -0500 (EST)

Hello,

I was working with the following probability distribution

P(Y) = 1/(6 (4 - Y)^(1/3)), for -4 < Y < 4

and I tried to check whether it would sum up to 1. But it didn't work
with Integrate:

Integrate[1/(6 (4 - Y)^(1/3)), {Y, -4, 4}] = 0

Clearly, the integral is 1. It is surprising that NIntegrate gives the
right answer:

NIntegrate[1/(6 (4 - Y)^(1/3)), {Y, -4, 4}] = 1.

Wolfram Alpha seems to have the bug as well:

http://www.wolframalpha.com/input/?i=integrate+1%2F%286+%284+-+Y%29%5E%281%2F3%29%29+from+-4+to+4

Cheers,
Daniel


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