Yes, I'm afraid that sign/asksign aren't very complete. In general,
sign/asksign doesn't do any sort of interval arithmetic or zero-finding to
determine signs.
assume(x>1,x<2);
sign(4*x-x^2) => pos <<< determined by factorization
sign(4*x-x^2+1) => pnz <<< can't factor, so gives up; interval arith
would give (4,8) - (1,2) + 1 = (3,8)
We should be able to do better!
-s
On Thu, Mar 22, 2012 at 01:54, <leon.magiera at wp.pl> wrote:
>
> I want to get the result of calculation (simplification)
>
> assume( x>0, x<%pi/2 );
> sign(cos(x));
>
> I expect to get 1, whereas MAXIMA returns:
>
> pnz
>
>
> Leon
>
>
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