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09/02/08 3:23pm

I have a simple nonlinear system of equations that I want Mathematica to solve for. Here is what I try and it fails.

t = ArcCos[n1 * 2 / Pi / F]
b = x / Cos[t]
x = Pi * F / 2 / n2
y = Sqrt[b^2 - x^2]
x^-2 + y^-2 = 4
Solve[%, n2]

Namely after the fifth equation Mathematica responds with what appears to me as a warning

Set::write: Tag Plus in .... is Protected.

The solver dies with this output

Solve::eqf: 4 is not a well-formed equation.

The answer I expect is
n2 = sqrt(Pi^2*F^2-4*n1^2)

Of course there is +- sqrt(...) to take into account, but I also know the following about my system that lets me eliminate the other answer
n1 >= 0
n2 >= 0
Pi*F >= 2*n1

So in short I want Mathematica to solve the system for n2, and I also want it to isolate the only valid answer given the restrictions above.


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Subject (listing for 'Trivial system of equations')
Author Date Posted
Trivial system of equations Ken 09/02/08 3:23pm
Re: Trivial system of equations Xavier 09/03/08 07:26am
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