The question states: F(x,y,z)=(y-z, 7z-8, x-7y). Compute line integral F.ds along the unit circle c(t)=(cos(t), sin(t), 0), 0<=t<=2pi.
So by doing the line integral F(c(t)).c'(t) you get -2pi. But how do you go about it using Stokes Theorem? What is the parametrization and what form of it would you use? Curl of F.dS?