this is what I've tried:
fy = 2y; fz=2z
A(S)=int int sqrt{1+4y^2 +4z^2}dA
then I switched to polar coordinates i tired to integrate from theta=0 to pi/2 and r= 0 to a
but didn't get anywhere with this.
Find the surface area of the the portions of the cylinder y^2 + z^2=a^2 bounded by x^2 + y^2 = a^2
not really sure how to go about this. tried to set up a double integral and use polar coordinates but don't know what boundaries to use etc.