PHP 5.4.33 Released

acos

(PHP 4, PHP 5)

acosArc cosinus

Description

float acos ( float $arg )

Retourne l'arc cosinus de arg. acos() est la fonction inverse de cos(), ce qui signifie que a==cos(acos(a)) pour toute valeur qui soit dans l'intervalle de validité de acos().

Liste de paramètres

arg

L'argument à traiter

Valeurs de retour

L'arc cosinus de arg, en radians.

Voir aussi

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User Contributed Notes 1 note

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zoltan dot szentesi at nokia dot com
8 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! :-)
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