COS

Description

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

Returns

A number; the cosine of the angle.

See also

ACos, Sin, ASin, Tan, Atn, Pi

Parameters

Usage

The range of the result is -1 to 1.

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 returns a very small number (such as 6.12323399574E-017) for angles that should produce 0. To test for a 0 value, check whether the value is less than 0.0000000000001.

Example

<h3>Cos Example</h3>
<!--- Calculate cosine if form has been submitted --->
<cfif IsDefined("FORM.cosNum")>
<!--- Make sure input is a number --->
   <cfif IsNumeric(#FORM.cosNum#)>
<!--- Convert degrees to radians, call the Cos function. --->
        <cfset cosValue=#Cos((Form.cosNum * PI()) / 180)#>
<!--- 0.0000000000001 is the function's precision limit.
     If absolute value of returned cosine value is 
     less, set result to 0 --->
        <cfif Abs(cosValue) LT 0.0000000000001>
           <cfset cosValue=0>
        </cfif>
        <cfoutput>
          Cos(#FORM.cosNum#) = #cosValue#<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 cosine:
    <br><input type = "Text" name = "cosNum" size = "15">
    <br><br>
    <input type = "Submit" name = "">&nbsp;&nbsp;
    <input type = "RESET"
</form>

NUMBER