二次函数y=ax~2+bx+c(a≠0),若令y=0,即为一元二次方程ax~2+bx+c=0(a≠0).由此可见,二次函数与一元二次方程之间有着密切的联系.用数形结合的思想来理解,对它们之间的内在联系的认识将更为深刻,更有利于灵活地解题,提高解题水平. The quadratic function y=ax~2+bx+c(a≠0), if let y=0, it is a quadratic equation ax~2+bx+c=0(a≠0). There is a close connection between sub-function and one-dimensional quadratic equation. Understanding with the combination of numbers and shapes, the understanding of the internal relations between them will be more profound, and it is more conducive to solving problems in a flexible manner and improving the level of problem solving.