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docko911

Member

Registered: 2008-05-15

Posts: 6

double integrals

docko911

Member

Registered: 2008-05-15

Posts: 6

Re: double integrals

evaluate

docko911

Member

Registered: 2008-05-15

Posts: 6

Re: double integrals

dydx

docko911

Member

Registered: 2008-05-15

Posts: 6

Re: double integrals

docko911

Member

Registered: 2008-05-15

Posts: 6

Re: double integrals

dydx

docko911

Member

Registered: 2008-05-15

Posts: 6

Re: double integrals

dydx

mathsyperson

Moderator

Registered: 2005-06-22

Posts: 4,900

Re: double integrals

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Why did the vector cross the road?
It wanted to be normal.

Dragonshade

Member

Registered: 2008-01-16

Posts: 147

Re: double integrals

Wow, looks like you cant even reverse the dy and dx, cuz lnx = ln0 is not define...kinda hard

Ricky

Moderator

Registered: 2005-12-04

Posts: 3,791

Re: double integrals

Unless you're taking complex analysis, you won't be able to solve this integral.  And even if you are, I have a feeling it diverges, though I'm not certain.

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"In the real world, this would be a problem.  But in mathematics, we can just define a place where this problem doesn't exist.  So we'll go ahead and do that now..."

docko911

Member

Registered: 2008-05-15

Posts: 6

Re: double integrals

evaluate \int_{0}^{\frac{\pi}{2}} \int_{x}^{\frac{\pi}{2}} \frac{\sin y}{y} dydx

i made a mistake it's sin y/y not x

docko911

Member

Registered: 2008-05-15

Posts: 6

Re: double integrals

evaluate

i made a mistake it's sin y/y not x

Online

Ricky

Moderator

Registered: 2005-12-04

Posts: 3,791

Re: double integrals

Even with that, you aren't going to get an answer using elementary functions.

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"In the real world, this would be a problem.  But in mathematics, we can just define a place where this problem doesn't exist.  So we'll go ahead and do that now..."

Dragonshade

Member

Registered: 2008-01-16

Posts: 147

Re: double integrals

Last edited by Dragonshade (2008-05-18 07:54:53)

Ricky

Moderator

Registered: 2005-12-04

Posts: 3,791

Re: double integrals

The bounds of integration with respect to x would be y to pi/2, not 0 to y.

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"In the real world, this would be a problem.  But in mathematics, we can just define a place where this problem doesn't exist.  So we'll go ahead and do that now..."

Dragonshade

Member

Registered: 2008-01-16

Posts: 147

Re: double integrals

The region should be the upper half of the rectangle divided by the line y=x, right? then I still think it should be 0 to y with respect to x

Ricky

Moderator

Registered: 2005-12-04

Posts: 3,791

Re: double integrals

Whoops...

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"In the real world, this would be a problem.  But in mathematics, we can just define a place where this problem doesn't exist.  So we'll go ahead and do that now..."