COS Function
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 Action

 Returns the cosine of an angle given in radians.


 Syntax

  COS( x)


 Remarks

 The argument  x can be of any numeric type.

 The cosine of an angle in a right triangle is the ratio between the length
 of the side adjacent to the angle and the length of the hypotenuse.

  COS is calculated in single precision if  x is an integer or
 single-precision value. If you use any other numeric data type,  COS is
 calculated in double precision.

 To convert values from degrees to radians, multiply the angle (in degrees)
 times --180
 (or .0174532925199433). To convert a radian value to degrees, multiply it by
 180-- (or 57.2957795130824). In both cases, - - 3.141593.


 See Also

  ATN,  SIN,  TAN


 Example

 The following example plots the graph of the polar equation r = nq for
 values of n from 0.1-1.1. This program uses the conversion factors x =
 cos(q) and y = sin(q) to change polar coordinates to Cartesian coordinates.
 The figure plotted is sometimes known as the Spiral of Archimedes.

 CONST PI = 3.141593
 SCREEN 1 . COLOR 7' Gray background.
 WINDOW (-4,-6)-(8,2) ' Define window large enough for biggest spiral.
 LINE (0,0)-(2.2 * PI,0),1' Draw line from origin to the right.

 ' Draw 10 spirals.
 FOR N = 1.1 TO .1 STEP -.1
    PSET (0,0)' Plot starting point.
    FOR Angle = 0 TO 2 * PI STEP .04
       R = N * Angle' Polar equation for spiral.
       ' Convert polar coordinates to Cartesian coordinates.
       X = R * COS(Angle)
       Y = R * SIN(Angle)
       LINE -(X,Y),1' Draw line from previous point to new point.
    NEXT Angle
 NEXT N