Java - Math acos() Method

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Description

The java.lang.Math.acos(double a) returns the arc cosine of an angle, in the range of 0.0 through pi.

If the argument is NaN or its absolute value is greater than 1, then the result is NaN.

A result must be within 1 ulp of the correctly rounded result. Results must be semi-monotonic.

Declaration

Syntax

public static double acos(double d)

Parameters

Here is the detail of parameters −

• d − A double data type.

Return Value

• This method returns the arccosine of the specified double value.

Example 1

In this example, we're showing the usage of Math.acos() method to get the acos of a double number. We've created a double variable x and initialized it with a given angle. Then using Math.toRadians() method we're retrieving the radian and then using Math.acos() method we've printed the acos value.

public class Test {
   public static void main(String args[]) {
      double degrees = 45.0;
      double radians = Math.toRadians(degrees);

      System.out.format("The value of pi is %.4f%n", Math.PI);
      System.out.format("The arccosine of %.1f degrees is %.4f%n", degrees, Math.acos(radians));
   }
}

This will produce the following result −

Output

The value of pi is 3.1416
The arccosine of 45.0 degrees is 0.6675

Example 2

In this example, we're showing the usage of Math.acos() method to get the acos of a float number. We've created a float variable x and initialized it with a given angle. Then using Math.toRadians() method we're retrieving the radian and then using Math.acos() method we've printed the acos value.

public class Test {
   public static void main(String args[]) {
      float degrees = (float)45.0;
      double radians = Math.toRadians(degrees);

      System.out.format("The value of pi is %.4f%n", Math.PI);
      System.out.format("The arccosine of %.1f degrees is %.4f%n", degrees, Math.acos(radians));
   }
}

This will produce the following result −

Output

The value of pi is 3.1416
The arccosine of 45.0 degrees is 0.6675

Example 3

In this example, we're showing the usage of Math.acos() method to get the cos of a zero value. We've created a float variable x and initialized it with a given angle for zero value. Then using Math.toRadians() method we're retrieving the radian and then using Math.acos() method we've printed the acos value.

public class Test {
   public static void main(String args[]) {
      float degrees = (float)0.0;
      double radians = Math.toRadians(degrees);

      System.out.format("The value of pi is %.4f%n", Math.PI);
      System.out.format("The arccosine of %.1f degrees is %.4f%n", degrees, Math.acos(radians));
   }
}

This will produce the following result −

Output

The value of pi is 3.1416
The arccosine of 0.0 degrees is 1.5708