ANother plot2d bug - can't plot limit sin(x)/x=1 when x->0

U-E59264-Osman F Buyukisik writes:
 > synthespian writes:
 >  > Hi-
 >  > 
 >  >  I can't do:
 >  > 
 >  > (C1) f2(x):=(sin(x)/x,x,1);
 >  > (C2) plot2d(f2(x),[x,-1,1]);
 >  > 
 >  >  Note that:
 >  > 
 >  >  x (rad)	y=sin(x)/x
 >  > +/- 1.0		0.84147
 >  >     0.9		0.87036
 >  >     0.8		0.89670
 >  >     0.7		0.92031
 >  >     0.5		0.94107
 >  >     0.4		0.95885
 >  >     0.3		0.97365
 >  >     0.2		0.98507
 >  >     0.1		0.99335
 >  >     0.01		0.99998
 >  > 
 >  > 
 >  >  What's plotted has a 90 degrees angle! I mean, really!
 >  >  (And I begin to wonder if xmaxima will help me pass my Calculus
 >  > class...)
 >  >  What's with plot2d?? What was the _last version_ when it was
 > 
 > Maxima 5.5 with gcl 2.3.8  seems to working OK. I get a fine plot:
 > 
 > (C12) f2(x):=sin(x)/x;
 > 
 >                                          SIN(x)
 > (D12)                           f2(x) := ------
 >                                            x
 > (C13) plot2d(f2(x),[x,-1,1]);
 > 
 > 
 > Why did you use  
 > f2(x):=(sin(x)/x,x,1);
 > instead of what I have above?
 > 
 > Osman
 >

Hi -

 Because I wanted it to tend to 1. Do you have any suggestions?
 Anyways, yet another weird bug. Try:

(C1) plot2d(f(x),[x,-40,40]);	 ;; plots Ok
(C2) plot2f(f(x),[x,-50,50]);	 ;; BUG - 
 Division by 0
 -- an error. Quitting. To debug this try DEBUGMODE(TRUE);)

 BTW, it has occurred to me that if you specify boundaries that are
very large (e.g., -10000,10000) you might get an "straight angle",
like I said in my first message. Again, that would be awkward for a
default behavior.

 This is Maxima 5.6 on debian potato.

 Regs
 Henry