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# Math.atan2

## Math.atan2

The `Math.atan2()` function returns the arctangent of the quotient of its arguments.

## Syntax

``Math.atan2(y, x)``

`y`
First number.
`x`
Second number.

## Description

The `Math.atan2()` method returns a numeric value between -π and π representing the angle theta of an `(x, y)` point. This is the counterclockwise angle, measured in radians, between the positive X axis, and the point `(x, y)`. Note that the arguments to this function pass the y-coordinate first and the x-coordinate second.

`Math.atan2()` is passed separate `x` and `y` arguments, and `Math.atan()` is passed the ratio of those two arguments.

Because `atan2()` is a static method of `Math`, you always use it as `Math.atan2()`, rather than as a method of a `Math` object you created (`Math` is not a constructor).

## Examples

### Using `Math.atan2()`

```Math.atan2(90, 15); // 1.4056476493802699
Math.atan2(15, 90); // 0.16514867741462683

Math.atan2(±0, -0);               // ±PI.
Math.atan2(±0, +0);               // ±0.
Math.atan2(±0, -x);               // ±PI for x > 0.
Math.atan2(±0, x);                // ±0 for x > 0.
Math.atan2(-y, ±0);               // -PI/2 for y > 0.
Math.atan2(y, ±0);                // PI/2 for y > 0.
Math.atan2(±y, -Infinity);        // ±PI for finite y > 0.
Math.atan2(±y, +Infinity);        // ±0 for finite y > 0.
Math.atan2(±Infinity, x);         // ±PI/2 for finite x.
Math.atan2(±Infinity, -Infinity); // ±3*PI/4.
Math.atan2(±Infinity, +Infinity); // ±PI/4.
```