The number pi and its use

["Dimitris Tsokakis" <TSOKAKIS@xxxx>]

We read from  
AFL Function Reference
 
SIN 



SYNTAX 
sin( NUMBER )sin( ARRAY )

RETURNS
NUMBER,ARRAY

FUNCTION 
Returns the sine of NUMBER or ARRAY. This function assumes 
that the ARRAY values are in radians.
 
COS 



SYNTAX 
cos( NUMBER )cos( ARRAY )

RETURNS
NUMBERARRAY

FUNCTION 
Returns the cosine of NUMBER or ARRAY. Assumes that the 
NUMBER or ARRAY values are in radians.
 
In the case you do not remember the 
relation between degs and radians
keep this note:
 
30 deg=pi/6 rad
45 deg=pi/4 rad
60 deg=pi/3 rad
90 deg=pi/2 rad 
180deg=pi   rad , 
etc
where pi is the 
3,14...
 
If you want pi automatically, use the 
formula
 
pi=4*atan(1);
 
So, if you want to use the sine of30 deg, 
sin(30) is wrong.
The correct is
 
pi=4*atan(1);
s1=sin(pi/6);
 
s1 now is the sine of 30 deg and is equal 
to 0.5
 
Sine and cosine are the available ways to 
find the value of an angle
and use it in quantitative 
calculations. 
 
Dimitris 
Tsokakis