DISCONTINUITIES IN A CURVE



On 10/31/2012 04:57 PM, Bernard LUCE wrote:
>
> As far as I understand, you discard the discontinuities in the curve 
> by avoiding the undefined value -2 and +1 and drawing on intervals 
> [t,-20,-2.1] ,[t,-1.9,0.9],[t,1.1,20].
>
> The pain is when the undefined values aren?t so quite obvious and we 
> have to trust Maxima to chase them away? I remember a very convenient 
> Maple plot-option like /?discont=true? /which masters all the stuff, 
> but apparently it hasn?t be implemented in Maxima ?
>
Not in plot2d. I do not know if other packages have something of that kind.

> PS concerning the stability of m1, m2, m3, the unicity of limit 
> principle shall suffice, shan?t it ? At the latest, testing MINUS 
> infinity as well could comfort m3 and a3 coefficients :
>
> m3: limit(g/f,t,minf) ; a3: m3*x + limit(g-m3*f,t,minf);
>
>
I agree. We should have also checked for the other two discontinuities:

(%i9) m1: limit(g/f,t,-2,minus);
(%o9)                           0
(%i10) m1: limit(g/f,t,-2,plus);
(%o10)                          0
(%i11) m2: limit(g/f,t,1,minus);
(%o11)                         - 3
(%i12) m2: limit(g/f,t,1,plus);
(%o12)                         - 3

Regards,
Jaime