With this function you can get the number PI.
This is done like this: acos(-1) === M_PI
acos
(PHP 4, PHP 5, PHP 7)
acos — Arc cosine
Description
float acos
( float
$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.
Parameters
-
arg -
The argument to process
Return Values
The arc cosine of arg in radians.
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User Contributed Notes 2 notes
nurlanovic at gmail dot com ¶
6 months ago
zoltan dot szentesi at nokia dot com ¶
11 years ago
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! :-)
