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 ⇤ ← Revision 7 as of 2014-10-10 20:25:45 → Size: 1635 Editor: PhilippWiesemann Comment: Changed wording for consistency. ← Revision 8 as of 2016-03-27 21:33:06 → ⇥ Size: 1628 Editor: PhilippWiesemann Comment: Updated category. Deletions are marked like this. Additions are marked like this. Line 69: Line 69: [[CategoryAPI]], [[CategoryAdditionalOther]] [[CategoryAPI]], [[CategoryStandard]]
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# SDL_acos

Use this function to compute arc cosine of x.

## Syntax

```double SDL_acos(double x)
```

## Function Parameters

 x floating point value, in radians

## Return Value

Returns arc cosine of x.

## Code Examples

```    /* acos(x) = Pi/2 - asin(x) */
SDL_Log("acos(0):\t\t%f", SDL_acos(0));
SDL_Log("Pi/2 - asin(0):\t%f\n", 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\n", M_PI - SDL_acos(-1));
```

## Remarks

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

## Version

This function is available since SDL 2.0.2.

None: SDL_acos (last edited 2016-06-10 19:54:38 by PhilippWiesemann)

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