###Function###
ATan

###Description###
Calculates the arctangent of a number.

###Syntax###
ATan ( expression )


###Parameters###
@@ParamTable@@
expression
	Any valid numeric expression.
@@End@@

###ReturnValue###
Returns the trigonometric arctangent of the number. Result is in radians.


###Remarks###
The result of <strong>4 * <a href="ATan.htm">ATan</a>(1)</strong> is pi.


###Related###
ACos, ASin, Cos, Sin, Tan


###Example###
@@IncludeExample@@
