Casio fxcg 500, FX CP 400

[Csaba Tizedes]

(01-24-2024 05:03 PM)ijabbott Wrote:  I got 2∠180 or 2∠π on an fx-9860GII and that is what I would expect to see in r∠θ mode. I would not expect to see −2 because a negative modulus makes no sense (or at least it would not be in the simplest form), mathematically. For what it's worth, HP calculators such as the HP-42S do the same thing.

If a student has no knowledge of complex numbers, then they shouldn't be setting the calculator to that mode!

Going back to the ClassPad II calculators, I don't have any...

So, you said, the selected mode is "forced" and not "possibility".
IMHO the -2 is simpler than 2<180.

Try the same in a+bi mode, you will see -2 instead of -2+0i means complex mode in a+bi form is a "possibility" and not "forced".
OR: try +2 in ANY mode and you'll get 2, not 2<0 or 2+0i

Yeah, I know, what you want to say, there is a huge difference between the two mode, is the understanding of the user, and you're right - but you miss a half step as CASIO missed also: between the two settings there is a third, as I want to see the result: reduced as possible: if a complex number has no imaginary part, that is a real, therefore I want to see a real number.

Your meaning means if you want to store a positive integer you must to use always the memory required for a complex number.

"Students" part is also not stands in reality, just try on fx-991EX the quadratics solver with one negative and one positive REAL roots but complex mode on, you will also got the above and try to explain this result to a student.

Cs.