Stokes theorem

Hi guys,

i have this question on stokes theoremn but dont know if the answer is correct would be great if someone could verify it!!! (Π = pi)



Let S be parametreised surface defined by

(a,b) ---(sin(a)cos(b),Sin(a)Sin(b) ,cos(a) )

where 0 ≤ a ≤ 2Π and 0≤ b ≤ Π/2
verify stokes theorem for the surface S and the Field F defined by F=(3y,-2y,z^2)


my answer is -3Π for both RHS and LHS of stokes theorem
is this right???


Thanks guys really appreciate it!