椭圆焦点在y轴上,设椭圆方程为x²/b² + y²/a² = 1 ,a＞b＞0交点坐标(x1,y1),(x2,y2)由题意得 (x1+x2)/2 = 1/2 ,∴x1+x2=1联立x²/b² + y²/a² = 1y=3x-2得x²/b² + (...