Description

Arctangent function. The arctangent is the angle whose tangent is number.

Returns

The arctangent, in radians, of a number.

Category

Mathematical functions

Function syntax

Atn(number)

See also

Atn, Sin, ASin, Cos, ACos, Pi

Parameters

Usage

The range of the result is -p/2 to p/2 radians. To convert degrees to radians, multiply degrees by p/180. To convert radians to degrees, multiply radians by 180/p.

Example

<h3>Atn Example</h3>
<!--- Output its Atn value. --->
<cfif IsDefined("FORM.AtnNum")>
    <cfif IsNumeric(FORM.AtnNum)>
        Atn(<cfoutput>#FORM.AtnNum#</cfoutput>) is
 <cfoutput>#Atn(FORM.AtnNum)# radians is #Atn(FORM.AtnNum * 180/PI())# Degrees</cfoutput>
    <cfelse>
<!--- If it is empty, output an error message. --->
        <h4>Enter a number</h4>
    </cfif>
</cfif>
<form action = "evaltest.cfm" method="post">
    <p>Enter a number to get its arctangent in Radians and Degrees
    <br><input type = "Text" name = "atnNum" size = "25"></p>
    <p><input type = "Submit" name = ""> <input type = "RESET"></p>
</form>