Java - Math atan() Method

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Description

The Java Math atan(double a) returns the arc tangent of an angle, in the range of -pi/2 through pi/2. Special cases −

• If the argument is NaN, then the result is NaN.

• If the argument is zero, then the result is a zero with the same sign as the argument.

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

Syntax

public static double atan(double d)

Parameters

Here is the detail of parameters −

• d − A double data type.

Return Value

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

Example 1

In this example, we're showing the usage of Math.atan() method to get the atan 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.atan() method we've printed the atan 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 arctangent of %.1f degrees is %.4f%n", degrees, Math.atan(radians));
   }
}

This will produce the following result −

Output

The value of pi is 3.1416
The arctangent of 45.0 degrees is 0.6658

Example 2

In this example, we're showing the usage of Math.atan() method to get the atan 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.atan() method we've printed the atan 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 arctangent of %.1f degrees is %.4f%n", degrees, Math.atan(radians));
   }
}

This will produce the following result −

Output

The value of pi is 3.1416
The arctangent of 45.0 degrees is 0.6658

Example 3

In this example, we're showing the usage of Math.atan() method to get the tan 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.atan() method we've printed the atan 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 arc tangent of %.1f degrees is %.4f%n", degrees, Math.atan(radians));
   }
}

This will produce the following result −

Output

The value of pi is 3.1416
The arc tangent of 0.0 degrees is 0.0000