Let c be the closed, piecewise smooth curve formed by traveling in straight lines between the points (0, 0, 0), (2, 0, 8), (3, 2, 12), (1, 2, 4), and back to the origin, in that order. (thus the surface s lying interior to c is contained in the plane z = 4x.) use stokes' theorem to evaluate the following integral. c (z cos(x)) dx + (x2yz) dy + (yz) dz