Tan

Description

Calculates the tangent of an angle that is entered in radians.

Returns

A number; the tangent of an angle.

Function syntax

Tan(number)

Parameters

Parameter	Description
number	Angle, in radians, for which to calculate the tangent.

Usage

To convert degrees to radians, multiply degrees by p/180. To convert radians to degrees, multiply radians by 180/p.

Note: Because the function uses floating point arithmetic, it can return a very small number (such as 6.12323399574E-017) for angles that should produce 0 and can return a very large number (such as 1.63312393532E+016) for infinity or not a number. To test for a 0 value, check whether the value is less than 0.0000000000001. To test for an infinite value, check whether the value is more than 1E15.

Example

<h3>Tan Example</h3>
<!--- Calculate tangent if form has been submitted --->
<cfif IsDefined("FORM.tanNum")>
<!--- Make sure input is a number --->
   <cfif IsNumeric(#FORM.tanNum#)>
<!--- Convert degrees to radians, call the Tan function. --->
        <cfset tanValue=#Tan((Form.tanNum * PI()) / 180)#>
<!--- 0.0000000000001 is the function's precision limit.
     If absolute value of returned value is 
     less, set result to 0 --->
        <cfif Abs(tanValue) LT 0.0000000000001>
           <cfset tanValue=0>
        </cfif>
        <cfoutput>
          Tan(#FORM.tanNum#) = #tanValue#<br><br>
        </cfoutput>
   <cfelse>
<!--- If input is not a number, show an error message --->
      <h4>You must enter a numeric angle in degrees.</h4>
   </cfif>
</cfif>
<form action = "#CGI.script_name#" method="post">
    Enter an angle in degrees to get its tangent:
    <br><input type = "Text" name = "tanNum" size = "15">
    <br><br>
    <input type = "Submit" name = "">&nbsp;&nbsp;
    <input type = "RESET"
</form>

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Tan