补上线段y = 0则令P = e^xsiny - y,dP/dy = e^xcosy - 1Q = e^xcosy - 1,dQ/dx = e^xcosy∫_L (e^xsiny - y) dx + (e^xcosy - 1) dy= ∫∫_D [(e^xcosy) - (e^xcosy - 1)] dxdy= ∫∫_D dxdy= 1/2 • π(1)...