13-18 Use Green's Theorem to evaluate Jc F . dr. (Check the orientation of the curve before applying the theorem.) 13. Jc (3 + ex?) dx + (tan ly + 3x?) dy x2 + y2 = 4 x2 + y- =1 0 1 2 x 14. Jc (x 2/3 + y ? ) dix + (14/3 - x2 ) dy YA (4, 2) x= y2 C 0 (4, 0) X