---
name: "fixtan"
section: "3alleg"
platform: "linux"
package: "liballegro-doc"
version: "2:4.2.2-2.2"
release: "Debian 6.0 (Squeeze)"
platforms: ["linux"]
url: "https://new.carta.tech/fixtan"
---

# fixtan(3alleg)

Fixed point tangent of binary angles. Allegro game programming library.

## NAME

fixtan - Fixed point tangent of binary angles. Allegro game programming library.

## SYNOPSIS

**#include \<allegro.h\>**

**fixed fixtan(fixed x);**

## DESCRIPTION

This function finds the tangent of a value using a lookup table. The input value must be a fixed point binary angle. Example:

```
   fixed angle, res_a, res_b;
   float dif;
   angle = itofix(37);
   /* Prove that tan(angle) == sin(angle) / cos(angle). */
   res_a = fixdiv(fixsin(angle), fixcos(angle));
   res_b = fixtan(angle);
   dif = fixtof(fixsub(res_a, res_b));
   allegro_message("Precision error: %f\n", dif);
```

## RETURN VALUE

Returns the tangent of a fixed point binary format angle. The return value will be in radians.

## SEE ALSO