Sin()
Returns the sine of <number> where <number> is expressed in <units>.
<units> may be 'radians', 'degrees', or 'gradians' or just the first letter of any of these. By default, <units> is radians.
In a circle, there are 2*pi() radians, 360 degrees, and 400 gradians.
Example
> say sin(270,d)
You say, "-1"
> say sin(fdiv(pi(),2))
You say, "1"
> say sin(fdiv(pi(),4))
You say, "0.707107"
> say sin(fdiv(pi(),6))
You say, "0.5"