说明：  给出二分法求函数零点的程序，要求如下： 调用条件：输入函数表达式f(x)，隔根区间[a,b] 输出结果：零点的值x和精度e. 给出调用说明和例子。
(The procedure of calculating function zeros by dichotomy is given. The requirements are as follows: Call conditions: input function expression f (x), interval [a, b] Output results: zero value x and precision E. Give the call description and examples.)