中学物理中的极值问题,包括求极值的条件,是一类重要的物理问题。求极值的方法通常用数学方法或用物理条件方法。用物理条件方法求极值,是根据物体之间的相互作用,针对具体的物理问题,通过详细分析物理状态,尤其是临界状态,物理过程的特点,作出判断,求得极值以及极值条件。它属于“具体的科学方法”。有些极值条件不容易从物理意义上一开始就分析出来,只好通过数学方法来求,用数学方法求极值,先要根据物理规律建立方程,再作一定的数学变换,把隐藏在物理量之间的复杂的极值关系揭示出来,从而求得极值和极值条件。常用的数学方法有三角函数法、二 The extremum problem in the middle school physics, including the condition of seeking extremum, is an important type of physical problem. The method of seeking extreme values ​​is usually mathematical or physical conditional. The use of physical conditions to find the extremum is based on the interaction between the objects and the specific physical problems. Through the detailed analysis of the physical state, especially the critical state, the characteristics of the physical process, to make judgments, to obtain the extreme and extreme conditions . It belongs to the “specific scientific method.” Some extremum conditions are not easily analyzed from the very beginning of the physical sense. They have to be solved by mathematical methods. Mathematical methods are used to find extremum. First, the equations must be established according to the laws of physics, and then some mathematical transformations must be made to hide the physical quantities. The complex extremum relationships are revealed to find the extreme and extreme conditions. Commonly used mathematical methods are trigonometric functions, two