### Table of Contents

# COS

(Defined in *TRIGONO.BAS*)

The `COS()`

function returns the cosine of the argument.

## Function Header

DECLARE FUNCTION COS AS FLOAT (arg AS FLOAT) SHARED STATIC

Warning

You must include the *TRIGONO.BAS* library in your program to be able to access this function.

## Examples

INCLUDE "trigono.bas" PRINT COS(0) : REM outputs .999403 PRINT COS(0.785398) : REM outputs .707704

Note

Trigonometric functions in XC=BASIC were designed to be fast rather than accurate. The result is accurate to 3 to 4 decimal digits (the error range is 0 to 0.0006). Please see this article for details.