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Re: Complex Number Simultaneous Equation 2 Unknowns

• To: mathgroup at smc.vnet.net
• Subject: [mg31533] Re: Complex Number Simultaneous Equation 2 Unknowns
• From: Tomas Garza <tgarza01 at prodigy.net.mx>
• Date: Fri, 9 Nov 2001 06:13:41 -0500 (EST)
• Approved: Steven M. Christensen <steve@smc.vnet.net>, Moderator
• References: <200111080956.EAA06472@smc.vnet.net>
• Sender: owner-wri-mathgroup at wolfram.com

Of course it's possible! The only thing is, you have to be extremely careful
with your syntax. You must enclose your set of equations in braces {}, not
parentheses (). The equal sign to be used is == (twice = ), since a single =
means assignment (Set). Then it goes beautifully. Now, in your example you
have \[ImaginaryI]0 in the rhs of the second equation, which I presume is a
typo, and Mathematica interprets it as a symbol "I0". Then

In[1]:=
Solve[{(2 + 4*I)*a + (1 + I)*b == 118 + 24*I,
   (1 + I)*a + (3 + I)*b == 110 + \[ImaginaryI]0}, {a, b}]

Out[1]=
{{a -> (-(5/74) - (7*I)/74)*(70 + 150*I - I*\[ImaginaryI]0),
   b -> (1/37 - (6*I)/37)*(63 + 149*I + (1 + 2*I)*\[ImaginaryI]0)}}

The solution comes always in terms of rules (check this in your Book or in
the Help browser). In this case, as you can see, the solution includes the
strange symbol "I0".

Tomas Garza
Mexico City
----- Original Message -----
From: "Removethisspamtrap_Martin Evans_ and this one too"
To: mathgroup at smc.vnet.net
<mcemail at dial.pipex.com>
Subject: [mg31533]  Complex Number Simultaneous Equation 2 Unknowns


> I've a simultaneous linear equation with complex numbers i'd like to
> put through Mathematica (I'm assuming this is possible!)
>
>
>
> Solve [((2 + 4\[ImaginaryI])*a) + ((1 + \[ImaginaryI])*b) = (118 +
>         24\[ImaginaryI]),
>
> ((1 + \[ImaginaryI])* a) + ((3 + \[ImaginaryI])*
>           b) = {110 + \[ImaginaryI]0},
>
> {a, b}]
>
> (all on one line but split for some sort of clarity here)
>
>
> I get this as the output:
>
> Set::"write": "Tag \!\(Plus\) in \!\(\(\(\(\((2 + \(\(4\\ \
> \[ImaginaryI]\)\))\)\)\\ a\)\) + \(\(\(\((1 + \[ImaginaryI])\)\)\\
> b\)\)\) is \
> Protected."
>
> Set::"write": "Tag \!\(Plus\) in \!\(\(\(\(\((1 + \[ImaginaryI])\)\)\\
> a\)\) \
> + \(\(\(\((3 + \[ImaginaryI])\)\)\\ b\)\)\) is Protected."
>
> General::"ivar": "\!\(110 + \[ImaginaryI]0\) is not a valid variable."
>
> Solve[118 + 24 \[ImaginaryI], {110 + \[ImaginaryI]0}, {a, b}]
>
> Any ideas as to what i'm doing wrong as the error messages don't make
> it obvious (at least to me as a 4 day old user!!)
>
> Also I seem to HAVE to use the esc ii esc where i would prefer to use
> lower case J (as an electrical eng) is there something special that
> needs to be done to use lower case J as in the help files it appears
> to be in bold
>
>
> --
>

• References:
  • Complex Number Simultaneous Equation 2 Unknowns
    • From: Removethisspamtrap_Martin Evans_ and this one too<mcemail@dial.pipex.com>