> (define pi 3.1415926535) pi> (sin pi) 8.979318433952318e-11
> (sin (/ pi 2)) 1.
> (sin (/ pi 6)) .4999999999870395
> (define pi 3.14159265358979)
> (sin pi) 3.2310891488651735e-15
> (sin (/ pi 6)) .49999999999999956
> (define pi 3.1415926535897932384)
> (sin pi) 1.2246467991473532e-16