椭圆x2/a2+y2/b2=1(a>b>0)通过伸缩变换变成单位圆,其变换有两个常用性质:①直线仍变成直线,斜率为原来的a/b.②平行于横轴(或在横轴上)的线段仍平行于横轴(或在横轴上),且长度为原来的1/a,平行于纵轴(或在纵轴上)的线段仍平行于纵轴(或 The ellipse x2/a2 + y2 / b2 = 1 (a> b> 0) is transformed into a unit circle by a scaling transformation. Its transformation has two common properties: 1 The straight line is still a straight line, and the slope is the original a/b.2 parallel. The line segment on the horizontal axis (or on the horizontal axis) is still parallel to the horizontal axis (or on the horizontal axis), and the length is 1/a, and the line segment parallel to the vertical axis (or on the vertical axis) is still parallel to Vertical axis (or