acos
(PHP 4, PHP 5)
acos — Arc cosine
Description
float acos
( float
$arg
)
Returns the arc cosine of arg in radians.
acos() is the complementary function of
cos(), which means that
a==cos(acos(a)) for every value of a that is within
acos()' range.
Parameters
-
arg -
The argument to process
Return Values
The arc cosine of arg in radians.