Let D1 be the region in the XY-plane enclosed by the triangle with vertices (0, 0),(1, 1).(2, 0). Let D2 be the semi-circular region of radius 1 with the center at (1, 0) lying below the x-axis. Let D...

Extracted text: Let D1 be the region in the XY-plane enclosed by the triangle with vertices (0, 0),(1, 1).(2, 0). Let D2 be the semi-circular region of radius 1 with the center at (1, 0) lying below the x-axis. Let D = D1 U D2. a) Argue whether D is an elementary region. b) Compute the area of D. c) Without using Green's theorem, evaluate f c(xydx + x²dy), where C denotes the boundary of D oriented clockwise. d) Use Green's theorem to evaluate the line integral given in part c).