Consider f and c below. f(x, y, z) = yz i + xz j + (xy + 10z) k c is the line segment from (2, 0, −2) to (6, 6, 1) (a) find a function f such that f = ∇f. f(x, y, z) = (b) use part (a) to evaluate c ∇f · dr along the given curve c.