求离心率的范围一直是高考圆锥曲线中的热点,由于这类问题涉及知识面广、综合性强、思路灵活,能较好地考查学生的思维能力以及运算能力,因此倍受高考命题者的青睐.本文结合实例谈谈离心率范围问题中构建不等关系的五个途径,希望对大家的学习有所借鉴.一、依据元素的有界性列出不等关系 Asking for the range of eccentricity has always been a hot spot in the college entrance examination conic curve. Since such questions involve a wide range of knowledge, strong comprehensiveness and flexible thinking, they can better examine students’ thinking abilities and computing abilities. Therefore, This article with examples to talk about the range of eccentricity in the construction of unequal relationship between the five ways in the hope of learning for everyone to learn from.First, according to the boundedness of elements listed unequal relations