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peacey
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Homework Statement
Find the Flux of the Vector Field <-1, -1, -y> where the surface is the part of the plane region z + x = 1 that is on the ellipsoid [tex]{x}^{2}+2\,{y}^{2}+{z}^{2}=1[/tex]
(oriented in the +ve z direction)
Homework Equations
Surface Integral
The Attempt at a Solution
Parametrize the Surface:
<u, v, 1 - u>
The intersection of the plane and the ellipsoid is:
[tex]{u}^{2}+2\,{v}^{2}+ \left( 1-u \right) ^{2}=1[/tex]
[tex]{u}^{2}+{v}^{2}=u[/tex]
Which is a circle of radius 1/2 centered at (1/2,0)
Or the polar region [tex]0\leq r\leq \cos \left( \theta \right) [/tex] and [tex]0\leq \theta\leq 2\,\pi [/tex]
Then, ru x rv = <1, 0, 1>
Then dotting the vector field with the above vector = -1 - v
So the integral becomes:
[tex]\int \!\!\!\int \!-1-v{dv}\,{du}[/tex]
After converting to polar and limits for the circle:
[tex]\int _{0}^{2\,\pi }\!\int _{0}^{\cos \left( \theta \right) }\!-r-{r}^{
2}\sin \left( \theta \right) {dr}\,{d\theta}
[/tex]
Which gives me [tex]-1/2\,\pi [/tex]
But, when I try to find the flux with maple by using the Flux command, it gives me -pi/4
Am I doing it wrong? Could someone point out where I went wrong please?
Thank you!
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