PHP asin () function
Examples
Returns the arcsine of different numbers:
<?php
echo(asin(0.64) . "<br>");
echo(asin(-0.4) . "<br>");
echo(asin(0) . "<br>");
echo(asin(-1) . "<br>");
echo(asin(1) . "<br>");
echo(asin(2));
?>
echo(asin(0.64) . "<br>");
echo(asin(-0.4) . "<br>");
echo(asin(0) . "<br>");
echo(asin(-1) . "<br>");
echo(asin(1) . "<br>");
echo(asin(2));
?>
Running instance »
Definition and Usage
asin () function returns the arc sine of a number.
Tip: asin (1) returns the value Pi / 2 in.
grammar
asin( number );
参数 | 描述 |
---|---|
number | 必需。规定一个数,范围在 -1 到 1 之间。 |
technical details
return value: | arc sine of number. If the number is not in the range between -1 and 1, then return to NAN. |
---|---|
Return type: | Float |
PHP version: | 4+ |
PHP Math Reference