Solve with dot products
- To: mathgroup at smc.vnet.net
- Subject: [mg70723] Solve with dot products
- From: Oliver Friedrich <xoliver.friedrich at tzm.dex>
- Date: Tue, 24 Oct 2006 02:24:43 -0400 (EDT)
Hallo,
I have some difficulties with interpretation of a solution that Solve
returns.
In[2]:=
Solve[a.b.c==d,a]
From In[2]:=
Solve::ifun: Inverse functions are being used by Solve, so some solutions
may \
not be found.
Out[2]=
{{a\[Rule]InverseFunction[Dot,1,3][d,b,c]}}
When I do that equation by hand I get something that I can't put into
correspondence with the solution above.
* means Inverse of a
(a.b)*=b*.a*
a.b.c=d |(_)*
c*.b*.a*=d* |c.
b*.a*=c.d* |b.
a*=b.c.d* |(_)*
a=d.c*.b*
b and c are swapped compared to the Mathematica solution.
1) Where's my error?
2) What's the interpretation of such an InverseFunction expression, I
don't get along the docu.
3) What's the z in InverseFunction[x,y,z][args] good for when I could
count the number of arguments in args?
Thanks a lot for your help
--
Regards
Oliver Friedrich
My email has no x!