Show that F(x, y) = −x i + −y j is a conservative force field. (x2 + y2)3/2 (x2 + y2)3/2

Use this fact to compute the work ∫C F ⋅ dr done by the force field in moving a particle along the curve C given by r(t) = (t3 − 3t) i + (t2 + t + 1) j, 0 ≤ t ≤ 2.