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。

 

package repeat_job1;

public class Cos {
    public Cos(){}
    public static double cos(double x)
    {
        double cos=1,numerator=1,denominator=1;
        int k=1;
        while(Math.abs(numerator/denominator)>1e-6)
        {
            numerator*=x*x;
            denominator *=- (2*k)*(2*k-1);
            cos+=numerator/denominator;
            k++;
        }
        return cos;
    }
    

}

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));
    }

}