# SQLite ATAN function

The SQLite ATAN function is a mathematical function that returns the arctangent of a given numeric expression. The arctangent, also known as the inverse tangent, is the angle whose tangent is a given number.

## Syntax

The syntax for the ATAN function in SQLite is as follows:

```ATAN(X)
```

Where X is the numeric expression for which you want to calculate the arctangent.

The ATAN function returns the arctangent of X in radians. If X is null, the function returns null.

### Example

Here’s an example of how to use the ATAN function in a SQLite query:

```SELECT ATAN(1.5);
```

This query returns the arctangent of 1.5 in radians, which is approximately 0.9828.

You can also use the ATAN function in conjunction with other mathematical functions to perform more complex calculations. For example, to calculate the angle of a right triangle given the lengths of its sides, you could use the ATAN function along with the SQRT (square root) and POW (power) functions:

```SELECT ATAN(b/a) * 180 / PI() as angle
FROM triangle
WHERE c = SQRT(POW(a,2) + POW(b,2));
```

In this query, the ATAN function is used to calculate the angle of the triangle, which is then converted from radians to degrees using the PI function. The SQRT and POW functions are used to calculate the length of the hypotenuse of the triangle.