在高中数学学习过程中以光线反射为代表的实际问题屡见不鲜,这类题型一般都是以光学为背景,以解析几何为支撑的,是一类常见的数学模型,所以在高考中的重要性也是不言而喻的。下面就此类问题进行探讨。一、利用入射光线、反射光线、界面及法线的对称性求解最值问题例1.已知点M(1,3),N(5,2),在x轴上求一点P,使得|PM|+|PN|最小。 In the high school mathematics learning process, the practical problems represented by light reflection are common. Such questions are generally based on optics and supported by analytical geometry. They are a common mathematical model, so the importance of college entrance examination It is also self-evident. The following discussion on such issues. First, the use of incident light, reflected light, the symmetry of the interface and the normal solution to the problem of the most value Example 1. Known point M (1,3), N (5,2), on the x-axis for a point P, so that PM|+|PN|min.