JavaScript atan – Find Arctangent and Inverse Tangent of Number

To find the arctangent, or inverse tangent, of a number, we can use the JavaScript atan() function from the math module.

Math.atan(x)

In JavaScript, we can easily use trigonometric functions with the JavaScript math module. The JavaScript math module allows us to perform trigonometry easily.

With the JavaScript math module, we can find the arctangent of a number easily.

To find the arctangent of a number, we use the math atan() function.

Below is the JavaScript syntax to find the inverse tangent of a number.

Math.atan(x)

The input to the atan() function must be a numeric value. The return value will be a numeric value between -pi/2 and pi/2 radians.

console.log(Math.atan(5))
console.log(Math.atan(0))
console.log(Math.atan(-3))

// Output: 
1.373400766945016
0.0
-1.2490457723982544

Finding the Inverse Tangent of a Number in JavaScript

Arctangent is defined as the inverse of the tangent of a number.

Below, we show that if we pass a number to tan() and then call the JavaScript atan() function, we get back the same number.

console.log(Math.atan(math.tan(math.PI/3)))
console.log(Math.PI/3)

// Output: 
1.0471975511965976
1.0471975511965976

Find Arc Tangent of the Quotient of Two Arguments with atan2() in JavaScript

JavaScript gives us the ability to find the arctangent of the quotient of two numbers, where the two numbers represents the coordinates of a point (x,y). To find the arctangent of a the quotient of two numbers, we use the math atan2() function.

Below is the JavaScript syntax to find the inverse tangent of the quotient of two numbers.

Math.atan2(x)

The inputs to the atan2() function must be a numeric values. The return value will be a numeric value between -pi and pi.

console.log(Math.atan2(5,1))
console.log(Math.atan2(0,0))
console.log(Math.atan2(-3,7))

// Output: 
1.373400766945016
0.0
-0.40489178628508343

Hopefully this article has been beneficial for you to understand how to use the math atan() function in JavaScript to find the arctangent of a number.