(1 point) Calculate S (2(x2 - y)i + 3(12 + x)j ) . dr if: (a) C is the circle (x - 4)2 + (y - 2)2 = 1 oriented counterclockwise. Jc (2(x2 - y)i + 3(12 + x )j ) . di = (b) C is the circle (x - a)2 + (y - b)2 = R2 in the xy-plane oriented counterclockwise. Sc ( 2( x2 - y)i + 3 (12 + x )j ) . di =