Surface integrals of vectors: Need check of my work- answer doesn't look right

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SUMMARY

The surface integral of the vector field F= over the surface defined by z=x^2+y^2, constrained by x^2+y^2 < 1, was evaluated using polar coordinates. The parametrization was correctly set as (rcos(theta), rsin(theta), r^2), and the normal vector was calculated as <2r^2cos(theta), 2r^2sin(theta), -r>. The dot product of the vector field F with the normal yielded the integrand (2r^3-r^2)(cos(theta)+sin(theta)), which was integrated over the limits r=0 to 1 and theta=0 to 2pi. The final result of the integral is confirmed to be π.

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Homework Statement


Find surface integral of vector field F=<x,y,x+y> over the surface z=x^2+y^2 where x^2+y^2 less than 1. Use outward pointing normals


Homework Equations





The Attempt at a Solution


So I did the whole thing and got a zero which doesn't look right to me. My algebra seems right so can you please validate the approach? Thanks:
I parametrize the surface in polar coordinates: x=r cos(theta) and y = r sin (theta). So my surface is (rcos(theta), rsin(theta), r^2).
I take partial derivatives of r and theta, find the determinant and my normal to the surface is < 2r^2cos(theta), 2r^2sin(theta), -r >
then F in terms of r and theta = < rcos(theta), rsin(theta), r(cos(theta)+sin(theta))>
dot product that with the normal to get (2r^3-r^2)(cos(theta)+sin(theta)) and integrate that for r= 0 to 1 and theta= 0 to 2pi
 
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Never mind- it was a calculation error... Answer is pi.
 

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