Re: Re[2]: Numeric inconsistency

[Raymond T. <to...@rt...>]

>>>>> "Arseny" == Arseny Slobodjuck <am...@ic...> writes:

    Arseny> Hello Raymond,
    Arseny> Thursday, July 18, 2002, 4:58:24 AM, you wrote:

    Raymond> Yes.  If you could, can you tell me why the computation of tan
    Raymond> requires the computation of sqrt?  Don't bother if it's lengthy.  Just
    Raymond> curious.
    Arseny> I have an supposition: it allows to compute only one of sin or cos, not both
    Arseny> (supposing sqrt being calculated more quickly than trigonometric function).
    Arseny> For example tg(a) = (+-)sqrt((1-cos(2a))/(1+cos(2a))).

Sounds reasonable.  Seems that this has lots of extra round-off
problems than just computing cos(a), though.

Ray