[Maxima] (1.0+%i)^0.5 does not evaluate numerically

[Richard Fateman]

I think this issue is that the original programmers hesitated to make a 
single choice of a multi-valued function.

For example, (-1)^(1/3)   is simplified to -1. Arguably, wrong.

(-1)^(1/3.0)
rectform(%)
gives 0.86602540378444*%i+0.5

That is another possibility.

If you plunge ahead and replace (-1)^(1/3.0) with  0.866*%i+0.5 you will 
undoubtedly get some answers more
directly. Probably you will be closer to what Mathematica does under 
similar circumstances.
You will presumably also get inconsistencies, as presumably does 
Mathematica.

Note that Mathematica does NOT do (-1)^(1/3) --> -1.

RJF