Java Math acos() Method

The acos() method of Math class computes the trigonometric Arc Cosine (inverse of cosine ) of an angle. The value returned is between 0.0 to pi.

Syntax:

public static double acos(double a)

Parameters:

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

Return Value:

The acos() method returns the arc cosine of the argument .

• If we pass a positive or negative argument which is in between the range of -1 to 1, it will return the arc cosine value.
• If we pass an argument which is smaller than -1 and greater than 1, it will return NaN.

Example 1:

public class JavaMathAcosExample1 {
    public static void main(String[] args) {
        double a=1/2;
        //return the arc cosine value for a
        System.out.println("Arc cosine value : "+Math.acos(a));
    }
}

Output:

Arc cosine value : 1.5707963267948966

Example 2:

public class JavaMathAcosExample2 {
    public static void main(String[] args) {
        double a=Double.MIN_VALUE;
        System.out.println("Arc cosine value for "+a+" = "+Math.acos(a));
    }
}

Output:

Arc cosine value for 4.9E-324 = 1.5707963267948966

Example 3:

public class JavaMathAcosExample3 {
    public static void main(String[] args) {
        double x = 1.00005;
        System.out.println("Arc cosine value for "+x+" = "+Math.acos(x));
    }
}

Output:

Arc cosine value for 1.00005 = NaN

Example 4:

public class JavaMathAcosExample4 {
    public static void main(String[] args) {
        double x= 7.0987;
        double y= Math.toRadians(x);
        System.out.println(Math.acos(y));
    }
}

Output:

1.4465814600932112