== Draft ==

'''THIS PAGE IS A WORK IN PROGRESS''' ... Please make edits to this page to improve it!



<!-- #*^*^*^*^*See https://wiki.libsdl.org/SGFunctions for details on editing this page*^*^*^*^* -->
= SDL_acos =

Use this function to compute arc cosine of <code>x</code>.

== Syntax ==

<syntaxhighlight lang='c'>
double SDL_acos(double x);
</syntaxhighlight>

== Function Parameters ==

{|
|'''x'''
|floating point value, in radians.
|}

== Return Value ==

Returns arc cosine of <code>x</code>.

== Remarks ==

The definition of <code>y = acos(x)</code> is <code>x = cos(y)</code>.

Domain: <code>-1 <= x <= 1</code>

Range: <code>0 <= y <= Pi</code>

== Version ==

This function is available since SDL 2.0.2.

== Code Examples ==

<syntaxhighlight lang='c++'>
/* acos(x) = Pi/2 - asin(x) */
SDL_Log("acos(0):\t\t%f", SDL_acos(0));
SDL_Log("Pi/2 - asin(0):\t%f", M_PI / 2 - SDL_asin(0));

/* acos(-x) = Pi  - acos(x) */
SDL_Log("acos(-(-1)):\t%f", SDL_acos(-(-1)));
SDL_Log("Pi - acos(-1):\t%f", M_PI - SDL_acos(-1));
</syntaxhighlight>

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[[CategoryAPI]], [[CategoryStandard]], [[CategoryDraft]]