二次函数是最简单的非线性函数之一,自身性质活跃,同时经常作为其他函数的载体·二次函数在某一区间上的最值问题,是初中二次函数内容的继续和发展,随着区间的确定或变化,以及在系数中增添参变数,使其又成为高考数学中的热点·一、定二次函数在定区间上的最值二次函数是给定的, The quadratic function is one of the simplest non-linear functions, and its nature is active. At the same time, it is often used as a vector function of other functions. The problem of the maximum value in a certain interval is the continuation and development of the content of the quadratic function in junior high school. The determination or change of the interval, and the addition of parametric variables in the coefficient, make it a hot spot in college entrance examination mathematics. First, the quadratic function of a given quadratic function over a fixed interval is given,