S is the portion of the paraboloid z5x25y2 that lies between

S is the portion of the paraboloid z=5x^2+5y^2 that lies between z=2 and z=6

z/5=(sqrt(z/5))²=x²+y²
I repeat my answer from here:
http://www.chegg.com/homework-help/questions-and-answers/s-portion-paraboloid-z-5x-2-5y-2-lies-z-2-z-6-q2680817

A parametrization is
x=sqrt(z/5) cos()

y=sqrt(z/5) sin()

z=z

2z6

02