Let F = 5 x^3 I + 1 y^3 J and let n be the outward unit normal vector to the positively oriented circle x^2 + y^2 = 9. Compute the flux integral ∫C F n ds.


I thought it would just be the double integral from 0,3 for both x and y of -15x^2-3y^2 muliplied by the area of the circle 3*pi.