6. (30 points) a) Let F = and r(t) =,0sts1

6. (30 points) a) Let F = < 4y5 ,20xy4 . Find a function f , so F = Vf . b) Use part a) and the Fundamental Theorem of Line Integrals to find F dr , where c F 3x2y2 and r(t) =