Problem 3 (12 pts) (a) Directly evaluate the line integral F . dr where F(x, y, z) = (yz + z, xz, xy+x) and C is the line segment from (0, 0, 0) to (1, 1, 1). (b) Find a function f(x, y, z) on R3 whose gradient equals F in (a) and evaluate the same line integral in (a) using the Fundamental Theorem of Line Integrals