PHP 8.1.0 Alpha 1 available for testing

asin

(PHP 4, PHP 5, PHP 7, PHP 8)

asinArc sine

Description

asin ( float $num ) : float

Returns the arc sine of num in radians. asin() is the inverse function of sin(), which means that a==sin(asin(a)) for every value of a that is within asin()'s range.

Parameters

num

The argument to process

Return Values

The arc sine of num in radians

See Also

add a note add a note

User Contributed Notes 1 note

up
0
rahmatjon at gmail dot com
4 months ago
Hello!
Please put this example below the asin() function's description.
Thank you!

Example:
<?php
    $arg
= 0.5;
   
$val = asin($arg);
    echo
"asin(" . $arg . ") = " . $val . " radians.<br/>";
    echo
"Pi value = " . pi() . "<br/>";  
    echo
"asin(" . $arg . ") = " . $val/pi()*180 . " degrees<br/>";

   
$arg = 1;
   
$val = asin($arg);
    echo
"asin(" . $arg . ") = " . $val . " radians.<br/>";
    echo
"Pi value = " . pi() . "<br/>";  
    echo
"asin(" . $arg . ") = " . $val/pi()*180 . " degrees<br/>";
?>
To Top