With this function you can get the number PI.
This is done like this: acos(-1) === M_PI
(PHP 4, PHP 5, PHP 7)
acos — Arc cosine
$arg
)
Returns the arc cosine of arg
in radians.
acos() is the inverse function of
cos(), which means that
a==cos(acos(a)) for every value of a that is within
acos()' range.
arg
The argument to process
The arc cosine of arg
in radians.
With this function you can get the number PI.
This is done like this: acos(-1) === M_PI
Wondering what is the use of 'acos' function?
It is essential in games, animations and drawings to determine the location of two objects relating to each other.
To the point: the angle of two vectors is calculated by
v1X*v2X + v1Y*v2Y
acos(--------------------------)=angle between two vectors.
|v1| * |v2|
|v1| and |v2| are the length of the vectors and calculated using Pithagoras-formula: |v1|=sqrt(v1X*v1X + v1Y*v1Y)
This helped me to calculate and share given space for 'n' amount of objects so that they don't overlap.
Enjoy! :-)