Calculate the integral of the surface facing positive, for the vector field $F (y, x, z) = (y, x, z)$ located on the surface $z = 9-x ^ 2-y ^ 2$ and the plane $z = 0$.
Well I try to solve this exercise with this integral
$\int_{-3}^{3} \int_{-\sqrt{9-x^2}}^{\sqrt{9-x^2}} \int_{0}^{9-x^2-y^2}1 dz dy dx=\frac{81\pi}{2}$
Am I ok??