# Function Reference

ATan

Calculates the arctangent of a number.

ATan ( expression )

Parameters

expression | Any valid numeric expression.

Return Value

Returns the trigonometric arctangent of expression. Result is in radians.

Remarks

The result of 4 * ATan(1) is pi.

Related

Sin, Cos, Tan, ASin, ACos

Example

$x = ATan(0.5)
$pi = 4 * ATan(1) ;equals 3.14159265358979
$radToDeg = 180 / $pi
$y = ATan(1) * $radToDeg ;arctangent of 1 returns 45°