[Overview][Constants][Types][Classes][Procedures and functions][Index] Reference for unit 'math' (#rtl)

# arctan2

Return arctangent of (y/x)

## Declaration

Source position: math.pp line 321

 function arctan2( y: Float; x: Float ):Float;

## Description

arctan2 calculates arctan(y/x), and returns an angle in the correct quadrant. The returned angle will be in the range $-\pi$ to $\pi$ radians. The values of x and y must be between -2\^{}64 and 2\^{}64, moreover x should be different from zero. On Intel systems this function is implemented with the native intel fpatan instruction.

 arccos Return inverse cosine arcosh Return inverse hyperbolic cosine arsinh Return inverse hyperbolic sine artanh Return inverse hyperbolic tangent

## Example

Program Example6;

{ Program to demonstrate the arctan2 function. }

Uses math;