Returns the arcsines of distinct numbers:
<?phpecho(asin(0.64) . "<br>");echo(asin(-0.4) . "<br>");echo(asin(0) . "<br>");echo(asin(-- 1) . "<br>");echo(asin(1) . "<br>");echo(asin(2));?>The asin() function returns the arcsine of a number.
Tip: asin(1) returns the value of Pi/2.
asin( number );
| parameter | describe |
|---|---|
| number | Required. Specifies a number ranging from -1 to 1. |
| Return value: | The arcsine of number . If number is not in the range -1 to 1, NAN is returned. |
|---|---|
| Return type: | Float |
| PHP version: | 4+ |