The inference of the intermediate value theorem shows that any number between these two values must have a function value of x value. And m and m are the maximum and minimum values of the function in this interval, so it is known that there must be a function value of x value corresponding to it without proof. Because if there is no function with x equal to m in this interval, how can m be the maximum value of this function in this interval? The same is true for m, so m and m know that there must be a function value of x to get these two numbers without proof. So what needs to be proved are those numbers that are greater than m and less than m.