(1 point) (a) Calculate the flux of the vector field F(x, y, z) = 8i - 9k through a sphere of radius 3 centered at the origin, oriented outward. Flux = (b) Calculate the flux of the vector field F(x, y, z) = 1 − 5] + 8k through a cube of side length 3 with sides parallel to the axes, oriented outward. Flux=