What is Math.acos() in Java?

Java has a built-in Math class in the java.lang package that contains important functions to perform basic mathematical operations.

The class contains the acos() method, which is used to compute the $\arccos$ or $cos^{-1}$ (pronounced “inverse cos”) of a specified value.

If $cos(\theta)$ is x, then $cos^{-1}$ (x) or $\arccos(x)$ is $\theta$ .

Return value

The function returns the double value corresponding to the $\arccos$ of value. The returned value will lie within the range $\pi/2$ to $-\pi/2$ .

Note: Math.PI is a constant equivalent to $\pi$ in mathematics.

If the value of value is infinity or NaNnot a number, then the returned value is NaN.

Note: To convert an angle measured in radians to an equivalent angle measured in degrees and vice versa, we can use the built-in Math.toDegrees(double angle_in_randians) and Math.toRadians(double angle_in_degrees) methods.

class HelloWorld {
    public static void main( String args[] ) {
        double result = Math.acos(1);
        System.out.println("acos(1) = " + result);
        result = Math.acos(0);
        System.out.println("acos(0) = " +  result);
        result = Math.acos(0.48);
        System.out.println("acos(0.48) = " + result);
        result = Math.acos(0.66);
        System.out.println("acos(O.66) = " + result);
        result = Math.acos(0.8);
        System.out.println("acos(0.8) = " + result);
        result = Math.acos(1);
        System.out.println("acos(1) = " + result);
        result = Math.acos(Double.NaN);
        System.out.println("acos(NaN) = " + result);
        result = Math.acos(Double.POSITIVE_INFINITY);
        System.out.println("acos(∞) = " + result);
    }
}

What is Math.acos() in Java?

Method definition

Parameters

Return value

Code