ATAN

Description

Function that returns the arctangent in radians of the number sent as a parameter (ATAN in Transact-SQL).

The arctangent is the inverse function of the tangent, summarized in the next definition: $y = arctan^{-1} \Leftrightarrow x = tan(x)$

For $y = tan^{-1}(x)$: - Range: $-\frac{\pi}{2}\leqslant y \leqslant \frac{\pi}{2}$ or $-90^{\circ}\leqslant y \leqslant 90^{\circ}$ - Domain: $\mathbb{R}$

Sample Source Pattern

Syntax

ATAN( expression )

Arguments

expression: Numeric float expression, or a numeric type which could be converted to float.

Return Type

Numeric float expression between $-\frac{\pi}{2}$ and $\frac{\pi}{2}$.

Examples

Query

SELECT ATAN(-30);

Result

ATAN(-30)          |
-------------------+
-1.5374753309166493|