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PHP atan() Function

< PHP Math Reference

Example

Return the arc tangent of different numbers with the atan() function:

<?php
echo(atan(0.50) . "<br>");
echo(atan(-0.50) . "<br>");
echo(atan(5) . "<br>");
echo(atan(-5) . "<br>");
echo(atan(100) . "<br>");
echo(atan(-100));
?>

Definition and Usage

The atan() function returns the arc tangent of arg as a numeric value between -Pi/2 and Pi/2 radians.

Syntax

atan(arg);

Parameter	Description
arg	Required. Specifies an argument to process

Technical Details

Return Value:	The arc tangent of arg in radians
Return Type:	Float
PHP Version:	4+

< PHP Math Reference