i have difficulties in solving the problem about stoke's theorem:

" Given u=(y+x2 ,3y,2xz)

surface: 1/4 of the circular cylinder 4=y2+x2 and z is on the interval I=[0,6]

verify the stoke's theorem over the region mentioned above."

Answer is -4(pi) but i could not find the answer.

i would be appreciated if anyone help me to solve this question.