一、与参数有关的区间上二次函数最值问题关于二次函数f(x)=ax~2+bx+c(a≠0)在[m,n]上的最值问题,解答时可通过置放二次函数图象的对称轴或所给区间,截取相应区间的图象获得最值,主要类型有以下三种:1.区间确定,对称轴位置待定例1求函数f(x)=2x~2-2ax+1在[-1,1]上的最小值. First, the parameter-related interval quadratic function most value problem On the quadratic function f (x) = ax ~ 2 + bx + c (a ≠ 0) in [m, n] By placing the symmetry axis or the given interval of the quadratic function image, the image of the corresponding interval is obtained to obtain the most value. The main types are as follows: 1. The interval is determined and the position of the symmetry axis is to be determined Example 1 Find the function f (x) = 2x ~ 2-2ax + 1 The minimum value on [-1,1].