在研究追赶类问题时,通过比较位移、时间等物理量来判断两个物体是否相遇是常见的思维方法。笔者发现,如果用一元二次方程的判别式和一元二次函数的极值来解析追赶类问题,不仅能理解数学表达式的物理意义,而且能提高学生运用数学知识来解决物理问题的能力。下面先对追赶类问题进行归类分析,列出一般情况下两个物体之间的相对 When studying the catching-up class, it is a common way of thinking to determine whether two objects meet by comparing physical quantities such as displacement and time. The author finds that if we solve the catch-up problem with the discriminant of the quadratic equation and the extremum of the quadratic function, we can not only understand the physical meaning of mathematical expressions, but also improve the ability of students to solve mathematical problems by using mathematical knowledge. The following first class to catch up with the classification analysis, listed under normal circumstances, the relative between the two objects