Help with this double integral

  • Thread starter eljose
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  • #1
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i would need help with this integral:

[tex] \int_a^{\infty}\int_a^{\infty}dxdyF(y/x) [/tex]

now i make the change of variable y/x=u x=v then what would be the new integration limits?..thanks.

where a can be 0 or 1
 
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Answers and Replies

  • #2
dextercioby
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U can't make that substitution. I hope you see why. Depending on the shape of the function "F", you may integrate directly. The integral may very easily diverge, but that wouldn't be a catastrophe, would it...?

Daniel.
 
  • #3
mathman
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You can make u the inner integral. The limits will be a/x to inf. and you will have 1/x in the integrand. v=x is irrelevant - it doesn't change anything.
 

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