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

The arctangent, in radians, of a number.

Mathematical functions

Atn(number)

Atn, Sin, ASin, Cos, ACos, Pi

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.

<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><input type = "Submit" name = ""> <input type = "RESET">
</form>