Java Math atan() Method

The atan() method of Math class computes the trigonometric Arc Tangent (inverse of tangent ) of an angle. The value returned is between -pi/2 to pi/2.

Syntax:

public static double atan(double a)

Parameters:

The parameter ‘a’ represents the value whose arc tangent is to be determined.

Return Value:

The atan() method returns the arc tangent of the argument .

• It returns NaN, if we pass a NaN .
• If we pass zero as an argument, it will return zero with the same sign as the argument.

Example 1:

public class JavaMathAtanExample1 {
    public static void main(String[] args) {
        double a=30;
        //return the arc tangent value for a
        System.out.println("Arc tangent value : "+Math.atan(a));
    }
}

Output:

Arc tangent value : 1.5374753309166493

Example 2:

public class JavaMathAtanExample2 {
    public static void main(String[] args) {
        //return the arc tangent value for Double.MIN_VALUE
        double a=Double.MIN_VALUE;
        System.out.println("Arc tangent value for "+a+" = "+Math.atan(a));
    }
}

Output:

Arc tangent value for 4.9E-324 = 4.9E-324

Example 3:

public class JavaMathAtanExample3 {
    public static void main(String[] args) {
        double x = Math.PI;
        System.out.println("Arc tangent value for "+x+" = "+Math.atan(x));
    }
}

Output:

Arc tangent value for 3.141592653589793 = 1.2626272556789115

Example 4:

public class JavaMathAtanExample4 {
    public static void main(String[] args) {
        //return an arc tangent value for infinity
        double x = 6/0.0d;
        System.out.println("Arc tangent value for "+x+" = "+Math.atan(x));
    }
}

Output:

Arc tangent value for Infinity = 1.5707963267948966

Example 5:

public class JavaMathAtanExample5 {
    public static void main(String[] args) {
        //return an arc tangent value for Nan
        double x = 0.0d/0.0d;
        System.out.println("Arc tangent value for "+x+" = "+Math.atan(x));
    }
}

Output:

Arc tangent value for NaN = NaN

Example 6:

public class JavaMathAtanExample6 {
    public static void main(String[] args) {
        //return an arc tangent value for negative Infinity
        double x = -90d/0.0d;
        System.out.println("Arc tangent value for "" = "+Math.atan(x));
    }
}

Output:

Arc tangent value for -Infinity = -1.5707963267948966