Solver question

[Nigel (UK)]

(06-16-2014 06:16 AM)HP67 Wrote:  Ok, I think I understand now. The SOLVER app does produce a real (wrong) result. This is confusing. Glad I tried ISOL first or I would been disappointed now

How are we supposed to use this effectively, and why doesn't it show the correct complex value for the solution like ISOL?

I think that the HP numeric solver has always behaved like this. If there is no root but there is an extremum it returns the extremum. The HP manuals for machines with this solver all have an appendix, discussing the solver's behaviour and how to interpret the results it returns, in which this issue is mentioned.

These earlier calculators were not aimed at students, however. Students don't read manuals! The Prime pops up an error box saying "Error: extremum found" which, I think, is a good approach. If the HP 39gii ever gets an update this would be a worthwhile change.

Slightly OT: I like the Prime a lot and have showed it to my students who also like it, but they are unlikely to spend about 100 UKP on a calculator. The HP 39gii is much cheaper and still an excellent machine, but I don't feel able to recommend it to them because it still has bugs and shows no sign of being supported. If HP wants to challenge Casio in UK schools they should not neglect the lower-priced end of the market.

Nigel (UK)