在近几年全国各地的数学竞赛和高考试题中,存在着大量的最值问题,笔者发现参考答案给出的方法并非都是好方法,有一些最值问题,若能用判别式去处理往往能收到事半功倍的效果,现结合往年的考题看看这种方法的功效.类型一、使用一次判别式例1(2014年浙江高考题)已知实数a,b,c,满足a+b+c=0,a~2+b~2+c~2=1,则a的 In recent years, mathematics competitions and college entrance examination questions all over the country, there are a large number of the most value problems, the author found that reference answers are not given are all good methods, there are some of the most value problems, if we can use discriminant to handle the often Can receive a multiplier effect, now combined with the test questions in previous years look at the effectiveness of this method. Type one, using a discriminant Example 1 (2014 Zhejiang college entrance examination questions) known real a, b, c, to meet a + b + c = 0, a ~ 2 + b ~ 2 + c ~ 2 = 1, then a’s