一元二次不等式的问题 ,在近年来的高考中 ,比重加大 .为了解决这类问题 ,可利用二次函数的图像的直观性来研究一元二次方程根的性质和一元二次不等式的解集及变化 .尤其对于含字母 (参数 )的有关问题的讨论 ,采用数形结合的思想 ,可使复杂的问题简单化 ,抽象的问题具体化 ,在 The problem of unary quadratic inequalities has increased in the proportion of college entrance examinations in recent years. To solve this type of problem, the quadratic function can be used to study the properties of the quadratic equation root and the solution of the unary quadratic inequality. Sets and changes. Especially for the discussion of related questions that contain letters (parameters), the idea of ​​using the combination of numbers and shapes makes it possible to simplify complex problems and to concretize abstract problems.