Need help with practice problem!

1. Suppose that C is an arbitrary positively oriented, piecewise-smooth, simple, closed curve that encloses the origin. Suppose that F(x, y) =- x 2 + 1 2 j and x 2 + G(x, y) =- 2xy i+ V - x (x2 + 12 )2 (x2 4 1,2)2 J . Prove the following statements: (a) F . dr = 2x (b) [G. dr = 0