Problem 15. (1 point) (1 pt) The domain of f(x, y) is the xy-plane, and values of f are given in the table below. Find fo grad f.dr, where C' is (a) A line from (1,0) to (3, 3). So grad f. dr = -5 (b) A circle of radius 1 centered at (1, 2) traversed counterclockwise. So grad f.dr Note: You can earn partial credit on this problem. yx 01234 0 60 60 61 61 61 1 5654 53 54 55 2 54 54 55 56 55 3 53 54 54 55 54 4 55 55 57 58 57