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