本文主要是总结一下现行统编教材中涉及到的最值问题的求法,以及在应用这些方法时要注意的问题。一、一元二次函数的最值 1.y=ax~2+bx+c(a≠0,x∈R)当x=-b/2a时,y(最值)=(4ac-b~2)/4a 2.y=ax~2+bx+c(a≠O,x∈[α,β])(1)-b/2a∈[α,β]时,y_(max)=max{f(-b/2a),f(α),f(β)} The purpose of this article is to summarize the approaches to the most value problems involved in current textbooks and the issues to be aware of when applying these methods. First, the value of the quadratic function of one yuan 1.y=ax~2+bx+c(a≠0,x∈R) When x=-b/2a, y(max value)=(4ac-b~2 )/4a 2.y=ax~2+bx+c(a≠O,x∈[α,β])(1)-b/2a∈[α,β], y_(max)=max{f (-b/2a),f(α),f(β)}