Let F(x, y, z) = xi + yj + zk. Evaluate the integral of F along each of the following paths. (a) c(t) = (3t, 3t, 3t), 0 t 1 (b) c(t) = (2 cos(t), 2 sin(t), 0), (c) c(t) = (2 sin(t), 0, 2 cos(t)), 0 t 6 0 t 6 (d) c(t) = (3t, t, 2t), -1 t 2