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||<tablewidth="100%" style="color: #FF0000;" :> DRAFT||

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= SDL_acos =
Use this function to compute arc cosine of '''x'''.




<<TableOfContents()>>


== Syntax ==
{{{#!highlight cpp
double SDL_acos(double x)
}}}




== Function Parameters ==
||'''x'''||floating point value, in radians||




== Return Value ==
Returns arc cosine of '''x'''.




== Code Examples ==
{{{#!highlight cpp

    /* 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));

}}}

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== Remarks ==
The definition of y = acos('''x''') is '''x''' = cos(y). <<BR>>
Domain: -1 <= x <= 1 <<BR>>
Range:   0 <= y <= Pi <<BR>>


== Version ==
This function is available since SDL 2.0.2.


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[[CategoryAPI]], [[CategoryStandard]]