- #1
DryRun
Gold Member
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Homework Statement
http://s2.ipicture.ru/uploads/20111231/kczcXUuF.jpg
The attempt at a solution
So, I'm using the transformation to spherical coordinates (ρ,∅,θ)
Description of region:
For θ and ∅ fixed, ρ varies from 0 to 4.
For θ fixed, ∅ varies from 0 to ∏. (i suspect the error is here)
θ varies from 0 to 2∏.
But i don't know what I'm doing wrong. I've checked my limits, but i think that's the problem, since i can't get the correct answer.
When i calculate ∅ by expanding into (ρrsin∅cosθ)^2 + (ρrsin∅sinθ)^2 = 4
Substituting r=2, i get the value of ∅ = ∏/6, which i also tested as the limits from 0 to ∏/6 and still got the wrong answer.
I then tested limits ∏/6 to 5∏/6 and still wrong.
Here is the answer from my notes:
http://s2.ipicture.ru/uploads/20111231/B1yTY1Ye.jpg
http://s2.ipicture.ru/uploads/20111231/kczcXUuF.jpg
The attempt at a solution
So, I'm using the transformation to spherical coordinates (ρ,∅,θ)
Description of region:
For θ and ∅ fixed, ρ varies from 0 to 4.
For θ fixed, ∅ varies from 0 to ∏. (i suspect the error is here)
θ varies from 0 to 2∏.
But i don't know what I'm doing wrong. I've checked my limits, but i think that's the problem, since i can't get the correct answer.
When i calculate ∅ by expanding into (ρrsin∅cosθ)^2 + (ρrsin∅sinθ)^2 = 4
Substituting r=2, i get the value of ∅ = ∏/6, which i also tested as the limits from 0 to ∏/6 and still got the wrong answer.
I then tested limits ∏/6 to 5∏/6 and still wrong.
Here is the answer from my notes:
http://s2.ipicture.ru/uploads/20111231/B1yTY1Ye.jpg
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