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Re: [Axiom-developer] bug in complexNormalize?
From: |
Waldek Hebisch |
Subject: |
Re: [Axiom-developer] bug in complexNormalize? |
Date: |
Sun, 27 Apr 2008 20:01:38 +0200 (CEST) |
> Any help on this would really be appreciated.
> Is it really a bug in complexNormalize?
>
> --S 5 of 14
> aa:=integrate(sinh(a*x)^2*cosh(a*x)^2,x)
> --R
> --R
> --R 3 3
> --R cosh(a x)sinh(a x) + cosh(a x) sinh(a x) - a x
> --R (1) -----------------------------------------------
> --R 8a
> --R Type: Union(Expression
> Integer,...)
> --E
>
> --S
> bb:=sinh(4*a*x)/(32*a)-x/8
>
> sinh(4a x) - 4a x
> (2) -----------------
> 32a
> Type: Expression Integer
> --E
>
> --S
> cc:=complexNormalize(aa-bb)
>
> (3) 0
> Type: Expression Integer
> --E
> @
> {\bf NOTE}, that if we compute this ``same'' expression directly
> we get a different answer. This appears to be a bug.
> --S
> dd:=complexNormalize(integrate(sinh(a*x)^2*cosh(a*x)^2,x)-sinh(4*a*x)/(32*a)-x/8)
>
> x
> (4) - -
> 4
> Type: Expression Integer
> --E
> @
>
I get:
complexNormalize(integrate(sinh(a*x)^2*cosh(a*x)^2,x)-(sinh(4*a*x)/(32*a)-x/8))
(5) 0
Type: Expression Integer
AFAICS the 'dd' expression lacks parentheses around copy of 'bb' term,
so you get 'x/8' with different sign.
--
Waldek Hebisch
address@hidden