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椭圆的离心率e=c/a= 反映了椭圆的扁圆程度,e越大,b/a越小,椭圆越扁;反之e越小,b/a越大,椭圆越圆.而以考察离心率为切入点的试题在高考中常常出现.求椭圆的离心率e时,常视c/a(或b/a)为一个整体. 一椭圆离心率的求解椭圆离心率的求解问题可以分三类:第一类由椭圆方程求离心率;第二类由椭圆定义求离心率:第三类由几何条件求离心率.其共同的过程是把a、c都求出来或转化成关于c/a的方程与
The eccentricity e of the ellipse e = c/a = reflects the oblateness of the ellipse. The larger e is, the smaller b/a is, and the ellipse is more flat, whereas the smaller e is, the larger b/a is, the ellipse is rounder. Eccentricity is the entry point of the test questions often appear in the college entrance examination. When the eccentricity of the ellipse e is calculated, often the c/a (or b/a) is a whole. An elliptical eccentricity solution to the elliptic eccentricity problem can be divided into Three types: the first type is the ellipse equation for the eccentricity; the second type is the ellipse definition for the eccentricity: the third type is to get the eccentricity from the geometric condition. The common process is to get or convert all a and c into c The equations for /a and