二次函数与一元二次方程有密切关系,要善于把它们联系起来处理问题,既能用函数观点解决方程问题,又能用方程思想处理函数问题.而数形结合是联系、解决二者的有效方法.抛物线与线段有交点的问题,也就是一元二次方程在某一条件下有解的问题,反之亦然,从数形结合角度可以很直观地解决.下举二例,供参考. Quadratic function and the quadratic equation are closely related, we should be good at linking them to deal with the problem, both to solve the equation function point of view problems, but also to deal with the function of the problem of equations. The combination of number is to contact and solve the two Effective method.Parabola and the line has a cross point problem, that is, a quadratic equation in a certain conditions have solutions to the problem, and vice versa, from the angle of the number of forms can be very intuitive to solve .In cite two cases for reference.