The asin() function returns the arc sine of a number.
float asin ( float $arg )
Returns the arc sine of arg in radians. asin() is the complementary function of sin(), which means that a==sin(asin(a)) for every value of a that is within asin()'s range.
Parameter | Description |
---|---|
number | Required. Specifies a number in range -1 to 1 |