Evaluating a Surface Integral: A Parallelogram

bugatti79
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Homework Statement



Evlute the surface integral

Homework Equations



f(x,y,z)=x+y+z where sigma is the parallelogram with parametric equations x=u+v, y=u-v and z=1+2u+v where 0 <=u<=2 and 0<=v<=1.



The Attempt at a Solution



I have no idea how to tackle this. Any suggestions?
 
on Phys.org
bugatti79 said:

Homework Statement



Evlute the surface integral

Homework Equations



f(x,y,z)=x+y+z where sigma is the parallelogram with parametric equations x=u+v, y=u-v and z=1+2u+v where 0 <=u<=2 and 0<=v<=1.



The Attempt at a Solution



I have no idea how to tackle this. Any suggestions?

You might begin by studying the material at:

http://tutorial.math.lamar.edu/Classes/CalcIII/SurfaceIntegrals.aspx
 
LCKurtz said:
You might begin by studying the material at:

http://tutorial.math.lamar.edu/Classes/CalcIII/SurfaceIntegrals.aspx

I believe we have to use [itex]\displaystyle \int \int _R f(x(u,v),y(u,v), z(u,v) || r_u \times r_v||dA[/itex]

I calculate the magnitude of the determinent to be \sqrt 2 hence

The surface integral becomes

[itex]\displaystyle \sqrt{2} \int_{0}^{1} \int_{0}^{2} (4u+v+1) du dv[/itex]...?
 
I agree with everything except the ##\sqrt 2##.
 
LCKurtz said:
I agree with everything except the ##\sqrt 2##.

since we have the determinant as 3i+1j-2k and the magnitude is

[itex]\sqrt(3^2+(-2^2)+1)=\sqrt 14[/itex] cheers
 
bugatti79 said:
since we have the determinant as 3i+1j-2k and the magnitude is

[itex]\sqrt(3^2+(-2^2)+1)=\sqrt 14[/itex] cheers

The ##\sqrt {14}## is correct, but 3i + j - 2k is not a determinant; it is a vector.
 

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