ColdFusion 9.0 Resources

Cos

Description

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

Returns

A number; the cosine of the angle.

Function syntax

Cos(number)

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 small number (such as 6.12323399574E-017) for angles that must 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 the absolute value  
    of the 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>

Cos