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flyingpig
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Homework Statement
Evaluate the surface integral
[tex]\iint_S y \; dS[/tex]
S is the part of the sphere [tex]x^2 + y^2 + z^2 = 1[/tex] that lies above the cone [tex]z=\sqrt{x^2 + y^2}[/tex]
The Attempt at a Solution
I know to use spherical coord so I did
[tex]r = <\rho cos\theta sin\phi, \rho sin\theta sin\phi, ?>[/tex]
The book did [tex]r = < cos\theta sin\phi, sin\theta sin\phi, cos\phi> [/tex]
I don't understand... why does [tex]z = \rho cos\phi [/tex]?
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