# Wiki Page Content

Differences between revisions 4 and 5
 ⇤ ← Revision 4 as of 2014-07-04 02:59:56 → Size: 1637 Editor: dthree Comment: Added linebreaks. ← Revision 5 as of 2014-07-04 03:01:42 → ⇥ Size: 1637 Editor: dthree Comment: Fixed my moinmoin syntax. Deletions are marked like this. Additions are marked like this. Line 56: Line 56: The definition of y = acos('''x''') is '''x''' = cos(y).
Domain: -1 <= x <= 1
Range: 0 <= y <= Pi
The definition of y = acos('''x''') is '''x''' = cos(y). <
>Domain: -1 <= x <= 1 <
>Range: 0 <= y <= Pi <
>
 DRAFT

# 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 in >= SDL 2.0.2.

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

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