一、命题的提出很多高中数学资料中有求形如y=a1x2+b1x+c1/a2x2+b2x+c2(a1,a2不全为0)的函数值域的求法的介绍.比如北京师大《高中数理化》2000年第1期第13页有下题:求函数y=x-3/x2-2x+5的最值. 在原文思路1中有一句话:由于分母x2-2x+5>0恒成立,故可将关于x的分式函数等价转化为关于x的整式方程. First, the proposition of the many high school mathematics materials in the form of a formula such as y = a1x2 + b1x + c1/a2x2 + b2x + c2 (a1, a2 not all 0) function range method of the introduction. For example, Beijing Normal University "high school Mathematical and physics, 2000, No. 1, page 13, has the following title: find the function y = x-3/x2-2x + 5 the most value. In the original thread of thinking 1 there is a sentence: Since the denominator x2-2x + 5> 0 Constant is established, so the fractional function on x can be equivalently transformed into the integral equation on x.