[BUG ?] Who can explain to me the CAS options "Use i" and "complex"?

[Arno K]

(04-03-2018 04:23 PM)dg1969 Wrote:  Arno I'm not sure I understand correctly. What is the use of this function czeros ? In what situation should I use it?

I take this thread to ask for some help. I understand that the "Complex" option means that variables can be complex. What is the difference with "Use i"?

czeros computes zeros of the given expression, that is something like 'x^2+x' is enough to be entered, you don't need to enter '...=0', solve is used for equations 'x^2+x=-3'.
If you check use i in CAS-settings, polynomials will be factored down to linear terms, without that 'factors (x^2+1)' results in {x^2+1,1}, with use i the output is {x+i,1,x-i,1}. Concerning Complex in CAS settings, I think that is always switched on, regardless to the mark there.
In Home settings you can decide if you want complex results show up as '1+3*i' or as '(1,3)', with that checkmark there you can enter sqrt(-1) and the result is i, wizhout the same input is commented as Error.
Arno