acos() - math

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 

Syntax

float acos
     ( float $arg
    )

Example

Output / Return Value

Limitations

Alternatives / See Also

Reference