# ASin

Returns the arcsine of a number in radians. The arcsine is the angle whose sine is number.

See also Sin, Cos, Pi, and Tan.

### Syntax

    ASin(number)

##### number

Sine of the angle that is to be calculated. This value must be between 1 and -1.

### Usage

The range of the result is -/2 to /2 radians. To convert degrees to radians, multiply degrees by /180. To convert radians to degrees, multiply radians by 180/.

### Examples

    <!--- This example shows how to use ASin --->

    <HTML>
    <HEAD>
    <TITLE>ASin Example</TITLE>
    </HEAD>

    <BODY BGCOLOR=silver>
    <H3>ASin Example</H3>
    <!--- output its arcsine value --->
    <CFIF IsDefined("FORM.SinNum")>
        <CFIF IsNumeric(FORM.SinNum)>
            <CFIF FORM.SinNum LESS THAN OR EQUAL TO 1>
                <CFIF FORM.SinNum GREATER THAN OR EQUAL TO -1>
                    ASin(<CFOUTPUT>#FORM.SinNum#</CFOUTPUT>) =
                      <CFOUTPUT>#Evaluate(ASin(FORM.sinNum))# Radians</
    CFOUTPUT>
                      <BR>
                      or
                      <BR>ASin(<CFOUTPUT>#FORM.SinNum#</CFOUTPUT>) =
                      <CFOUTPUT>#Evaluate(ASin(FORM.sinNum) * 180/Pi())#
    Degrees</CFOUTPUT>
                <CFELSE>
    <!--- if it is less than negative one, output an error message --->
                <H4>Please enter the sine of the angle that is to be
    calculated in degrees and radians. This value must be between 1 and -1,
    inclusive.</H4>
                </CFIF>
            <CFELSE>
    <!--- if it is greater than one, output an error message --->
            <H4>Please enter the sine of the angle that is to be calculated in
    degrees and radians. This value must be between 1 and -1, inclusive.</H4>
            </CFIF>
        <CFELSE>
    <!--- if it is empty, output an error message --->
            <H4>Please enter the sine of the angle that is to be calculated in
    degrees and radians. This value must be between 1 and -1, inclusive.</H4>
        </CFIF>
    </CFIF>

    <FORM ACTION="asin.cfm" METHOD="POST">
    <P>Type in a number to get its arcsine in Radians and Degrees.
    <BR><INPUT TYPE="Text" NAME="sinNum" size="25">
    <P><INPUT TYPE="Submit" NAME=""> <INPUT TYPE="RESET">
    </FORM>

    </BODY>
    </HTML>