12. Verify that the fundamental theorem of line integrals does not hold for the nonconservative vector field F(x, y) = x2i + xyj by the following steps. a) Demonstrate that the vector field is not conservative. b) Evaluate J. F . Tds, where C is a line from the point (0, 0) to the point (1, 1). c) Evaluate J. F . Tds, where C is the curve (t, t2), 0