Problem with zeros and solve in HP Prime.

[John P]

Thanks to all. Everything works great now. Something was messing up because I wasn't consistent with strings. IMHO when you write a prgm. in CAS: USE STRINGS AND BE CONSISTENT WITH STRINGS.
As for the output: I put everything in a list of list (curly brackets) so I have:
- in the first row {fn, fd, sd}
- in second row { roots, critical points, inflection points}
- in third row { sign(sd(crit. pts.)), f(crit.pts.), sd(inf.pts.)}
This way everything that relates: to the fn is in the 1st col, to the fd is in the 2nd col. and to the sd in the 3rd col. and I have the output in one piece so I can save it for later if I need to.
When the prgm. returns the out. I do factor(out.) so I get everything in nice matrix and can approximate or round it to desired precision.