[Maxima] exp(%i*%pi/4) not simplified
drdieterkaiser at web.de
Sat Jul 25 10:54:45 CDT 2009
Am Samstag, den 25.07.2009, 08:24 -0700 schrieb Richard Fateman:
> It is generally a serious problem to have two representations for the
> same thing, and so there are probably
> places where sqrt(x) or something similar is entirely bypassed, and
> only x^(1/2) is generated.
> So a rule that operates only on $sqrt may not be so effective unless the
> user actually types in sqrt().
> I think this needs more testing, e.g. rat(x^(3/2)) subst (1.2,x,%) ?
we do not have two representations for the sqrt function. The name
"sqrt" is only visible to the user on the display. Internally sqrt is
always represented as
((mexpt) x ((rat) 1 2))
Therefore we can declare a rule for sqrt(x) or x^(1/2). It is the same.
(%o2) [^rule1, simpexpt]
The Lisp call ($sqrt x) immediately simplifies the sqrt function to the
internal representation. In the last commit I have moved some special
code from the simplifying function simpsqrt to simpexpt to get sqrt(x)
and x^(1/2) really identical.
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