Cos |
Description
Calculates the cosine of an angle that is entered in radians.
Returns
A number; the cosine of the angle.
Category
Mathematical functions
Function syntax
    Cos(number)
See also
ACos, Sin, ASin, Tan, Atn, Pi
Parameters
Parameter | Description
number | Angle, in radians, for which to calculate the cosine
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 |
Angle, in radians, for which to calculate the cosine