HP 48SX real/complex algebra

[bxparks]

(06-26-2024 01:15 AM)Rick314 Wrote:  'RE((RE(A)+RE(B)*i)*(RE(C)+RE(D)*i)' EVAL on the 48SX makes no change to the expression. That may be the result of this thread and is why I brought it up -- I was surprised that the 48SX doesn't seem to be able to do this seemingly simple operation that other symbolic algebra systems can do.

I didn't even realize that the HP-48 series was considered to have a CAS system. But I see from this thread from 8 months ago (CAS & 48SX/GX), that it is considered to have "limited CAS".

Coincidentally, I was consulting my TI-89/92+ manual today, and I came across this tidbit: the TI-89/92+ considers all undefined single-letter variables (a-z) to be Real. To include a complex variable, we can append an underscore (_) after the name (e.g. a_, or z_). So for this problem, I entered:

real((a+b*i)*(c+d*i) + z_)

and got

a · c - b · d + real(z_)

Pretty impressive for a calculator that I picked up a few weeks ago for $14.