物理学中常会遇到力、加速度、速度的极值问题。目前中学对极值的求解多依赖于初等数学,即选定参量θ,写出含有参量θ的方程F(x、θ)=0,解出x的函数形式x=f(θ),讨论θ的取值对x的影响,求出x的极值,这种方法不失为中学求解极值问题最为规范的方法,但这种方法对数学要求较高,一部分学生感到困难。实际上力、加速度、速度都是矢量,矢量合成遵从三角形法则(或平行四边形法则),如果 In physics, you often encounter extreme problems of force, acceleration, and speed. At present, the middle school’s solution to extreme values ​​depends on elementary mathematics, that is, the selected parameter θ, the equation F(x, θ)=0 containing the parameter θ is written, and the function form of x is solved as x=f(θ). The value of x is determined by the value of x, which is the most standardized method for solving the extreme problem in middle school. However, this method has high mathematics requirements and some students find it difficult. Actually, force, acceleration, and speed are all vectors. Vector synthesis follows the law of triangles (or the law of parallelograms) if