Max Lipsky <maxlipsky@gmail.com> writes:
> SELECT acos(
> cos(radians(48.9193))
> * cos(radians(48.9193))
> * cos(radians(2.5431) - radians(2.5431))
> + sin(radians(48.9193))
> * sin(radians(48.9193))
> ) as result;
> This returned [22003] ERROR: input is out of range
Not too surprising, because (at least on my machine)
regression=# select cos(radians(48.9193))
regression-# * cos(radians(48.9193)) + sin(radians(48.9193))
regression-# * sin(radians(48.9193));
?column?
--------------------
1.0000000000000002
(1 row)
Problems of this sort are inevitable when working with finite-precision
math.
https://en.wikipedia.org/wiki/Round-off_error
regards, tom lane
