PHP acos () function
Examples
Returns the inverse cosine different numbers:
<?php
echo(acos(0.64) . "<br>");
echo(acos(-0.4) . "<br>");
echo(acos(0) . "<br>");
echo(acos(-1) . "<br>");
echo(acos(1) . "<br>");
echo(acos(2));
?>
echo(acos(0.64) . "<br>");
echo(acos(-0.4) . "<br>");
echo(acos(0) . "<br>");
echo(acos(-1) . "<br>");
echo(acos(1) . "<br>");
echo(acos(2));
?>
Running instance »
Definition and Usage
acos () function returns the inverse cosine of a number.
Tip: acos (-1) returns the value of Pi.
grammar
acos( 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: | number of inverse cosine. 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