(-1)^(1/4)?



>>>>> "Jay" == Jay Belanger <belanger@truman.edu> writes:

    Jay> Raymond Toy <toy@rtp.ericsson.se> writes:
    >> Currently, maxima says
    >> 
    >> (C21) solve(x^4+1=0,x);
    >> 
    >> 1/4		   1/4		   1/4		    1/4
    >> (D21) [x = (- 1)    %I, x = - (- 1)   , x = - (- 1)    %I, x = (- 1)   ]
    >> 
    >> which is right, but I expected the answer to be powers of
    >> (1+%i)/sqrt(2).  I could add the rule
    >> 
    >> tellsimp((-1)^(1/4), (1+%i)/sqrt(2))
    >> 
    >> to get what I want.
    >> 
    >> A bug?
    >> 
    >> Ray

    Jay> I wouldn't think so.  (1+i)/sqrt(2) is only the principal value of
    Jay> (-1)^(1/4), not *the* value.  The principal value of complex functions
    Jay> isn't always called for.

Yes, but then I'd have to ask why

sqrt(-1) is %i and not (-1)^(1/2)

Anyway Boris gave me a way to get the rectangular form which is good
enough for what I was trying to do (convert an elliptical integral to
one of the canonical forms).

Ray