求解cos（x）值

输入x值，按照公式计算cos(x)的值，直到最后一项小于10-6为止。

 

 1 package repeat_job1; 2  3 public class Cos { 4     public Cos(){} 5     public static double cos(double x) 6     { 7         double cos=1,numerator=1,denominator=1; 8         int k=1; 9         while(Math.abs(numerator/denominator)>1e-6)10         {11             numerator*=x*x;12             denominator *=- (2*k)*(2*k-1);13             cos+=numerator/denominator;14             k++;15         }16         return cos;17     }18     19 20 }

import repeat_job1.Cos;import java.util.Scanner;public class Test3 {    public static void main(String[] args)    {        Scanner reader=new Scanner(System.in);        System.out.println("请输入x：");        double x=reader.nextDouble();        reader.close();        System.out.println("cos("+x+")="+Cos.cos(x));    }}