3. Let / = (ycos(a), sin(a) + 2y) be a vector field and Car(t) = (2sint, cost), 0 2 tS * be a smooth curve. Use this to answer the following questions. (a) Show that F is conservative. (b) Find a potential function f such that F = Vf. (c) Use the Fundamental Theorem of Line Integrals to evaluate F . di