This topic has been discussed in this forum for some time, and I would like to give my experience on that.

First of all, I am not an engineer, and I have never use complex number to solve real world problems. Somebody earlier in this forum recommend an excellent book "the history of the square root of minus one", and so I bought one, and started calculating complex numbers on my 35S.

35S is heritaged from 32SII and 33S, and the complex number support for the latter two calculators are awkward. I originally assumed that it would be equally awkward for the 35S, and surprisingly, it found it very pleasant to use. This is mainly due to the primary button for i. I don't need to care for the limited 4 stacks, and in fact, I think entering complex numbers in 35S is as simple as entering real numbers, and is the easiest among any HP calculators I've used before, including 42S and 48G.

One of the main drawbacks people complain about HP35S (and 32SII and 33S) is its limited complex number support. For example, somebody here said that it should have supported ln(-2), arcsin (2), etc. I don't know, but I just wonder, how many times you would ever need to calculate arcsin (2) in real world problems? Maybe some professionals here need to, then would you please inform me about that.

Best regards,

KC