acos ( x -- y )
Factor handbook » The language » Numbers » Mathematical functions » Trigonometric and hyperbolic functions

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Vocabulary
math.functions

Inputs and outputs

x	a number
y	a number

Word description
Inverse trigonometric cosine.

Definition

USING: kernel math math.constants math.libm ;

IN: math.functions

: acos ( x -- y )
    dup [-1,1]? [ >float facos ] [ asin pi 2 / swap - ] if ;
    inline