费马光行最速原理的另一种数学论证

Another Mathematic Method to Prove Fermi Theory about the Travel of Light at the Highest or the Lowest Speed

利用初等函数的单调性、连续性论证了著名的费马光行最速原理 .

This argumentation continuously proves the famous theory by Fermi-the travel of light at the highest or the lowest speed, which is obtained with the method of the monotony of Primary Function