Java Math cos()方法及实例

java.lang.Math.cos() 返回一个角度的三角余弦。如果参数是 NaN或无穷大 ，那么返回的结果是NaN。返回的值将在 [-1, 1] 范围内 。

语法 :

public static double cos(double angle)

参数。
该函数有一个强制性参数angle，单位是弧度。

返回：

该函数返回一个角度的三角余弦。

例1： 展示java.lang.Math.cos()方法的工作。

// Java program to demonstrate working// of java.lang.Math.cos() methodimport java.lang.Math;  class Gfg {      // driver code    public static void main(String args[])    {        double a = 30;                  // converting values to radians        double b = Math.toRadians(a);          System.out.println(Math.cos(b));          a = 45;                  // converting values to radians        b = Math.toRadians(a);          System.out.println(Math.cos(b));          a = 60;                  // converting values to radians        b = Math.toRadians(a);          System.out.println(Math.cos(b));          a = 0;                  // converting values to radians        b = Math.toRadians(a);          System.out.println(Math.cos(b));    }}

输出:

0.86602540378443870.70710678118654760.50000000000000011.0

例2： 展示当参数为NAN或无穷大时，java.lang.Math.cos()方法的工作。

// Java program to demonstrate working// of java.lang.Math.cos() method infinity caseimport java.lang.Math; // importing java.lang package  public class GFG {    public static void main(String[] args)    {          double positiveInfinity =                Double.POSITIVE_INFINITY;        double negativeInfinity =                Double.NEGATIVE_INFINITY;        double nan = Double.NaN;        double result;          // Here argument is negative infinity,         // output will be NaN        result = Math.cos(negativeInfinity);        System.out.println(result);          // Here argument is positive infinity,         // output will also be NaN        result = Math.cos(positiveInfinity);        System.out.println(result);          // Here argument is NaN, output will be NaN        result = Math.cos(nan);        System.out.println(result);    }}

输出:

NaNNaNNaN