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Student Support Forum: 'triple integrals order of dxdydt' topicStudent Support Forum > General > Archives > "triple integrals order of dxdydt"

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Ned Moore
09/23/08 2:27pm

hi,
I'm using v6.0 for students. I'm trying to integrate two arbitrary functions, w and delta w, of independent variables x,y, and t. The following code works properly:
Integrate[
Times[Derivative[2, 0, 0][w][x, y, t],
Derivative[2, 0, 0][\[Delta]w][x, y, t]], t, y, x]

The following (basically identical) code does not work properly
Integrate[
Times[Derivative[2, 0, 0][w][x, y, t],
Derivative[2, 0, 0][\[Delta]w][x, y, t]], x, y, t]

It doesn't do much of anything, in fact. It just returns the same integral as the input, whereas the first one returns a sum of a double integral and a triple integral, which is exactly what I want. All that I changed was the order of dxdydt from t,y,x to x,y,t, which doesn't seem like it should matter. Code is attached.

I'm afraid that I'll have to make a pattern to reorder the dxdydt's, which sounds terrible. Help!

Thanks
Ned

Attachment: WhatTheHeck.nb, URL: ,

Subject (listing for 'triple integrals order of dxdydt')
Author Date Posted
triple integrals order of dxdydt Ned Moore 09/23/08 2:27pm
Re: triple integrals order of dxdydt Kaveh 09/23/08 7:04pm
Re: Re: triple integrals order of dxdydt Ned Moore 09/23/08 7:49pm
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