Understanding the Math.atan() Method in JavaScript

The Math.atan() method in JavaScript returns the arctangent (inverse tangent) of a given number, expressed in radians. This method is often used to find the angle whose tangent is the provided number, with results ranging between \(-\pi/2\) and \(\pi/2\) radians, or approximately -1.57 to 1.57.

Key Points About Math.atan()

1. Input Range: Math.atan() accepts any real number as input, as all real numbers have a defined arctangent.
2. Output Range: The output is constrained between \(-\pi/2\) and \(\pi/2\) radians.
3. Special Cases:
   1. Passing null returns 0, as it is treated as zero in calculations.
   2. Non-numeric strings or undefined values result in NaN (Not-a-Number), signaling an invalid input.

Syntax

Math.atan(n);

Where n is the number you want to find the arctangent of.

Example Usage of Math.atan()

Here's how Math.atan() handles various types of inputs:

<script>
    var arctangentNegativeOne = Math.atan(-1);
    document.writeln('Arctangent of -1: ' + arctangentNegativeOne + '

');
    
    var arctangentNull = Math.atan(null);
    document.writeln('Arctangent of null: ' + arctangentNull + '

');
    
    var arctangentOne = Math.atan(1);
    document.writeln('Arctangent of 1: ' + arctangentOne + '

');
    
    var arctangentPositive = Math.atan(10);
    document.writeln('Arctangent of 10: ' + arctangentPositive + '

');
    
    var arctangentString = Math.atan('Labw3');
    document.writeln('Arctangent of "Labw3" (Invalid String): ' + arctangentString + '

');
</script>

Output

Arctangent of -1: -0.7853981633974483
Arctangent of null: 0
Arctangent of 1: 0.7853981633974483
Arctangent of 10: 1.4711276743037347
Arctangent of "Labw3" (Invalid String): NaN