Mathematica Solving equation in Mathematica

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The discussion revolves around a coding issue related to finding parameters Na and Q in an equation that equals 10^{-10}. The original approach using the Solve function was unsuccessful, leading to the suggestion that numerical solutions could be obtained using FindRoot instead. It was noted that analytical solutions are not always possible for all equations, and the syntax for FindRoot differs from Solve. Users are encouraged to consult the help menu for guidance on the new syntax and examples to effectively implement FindRoot.
EngWiPy
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Hello,

I have the following code to find the parameters Na and Q that make the expression equals 10^{-10}:

Code:
Na =.;
Q =.;
MGF[s_, gC_] := 1/(1 - gC*s);
SNRdB = 0;
SNR = 10^(SNRdB/10);
gC = 0.5*SNR;
p = gA*gB;
A = 23;
Solve[((E^(A/2)*2^-Q)/SNR \!\(
\*UnderoverscriptBox[\(\[Sum]\), \(q = 0\), \(Q\)]\(-
\*SuperscriptBox[\(1\), \(Na + q + 1\)]\)*Binomial[Q, q]*Re[
\*FractionBox[\(MGF[\(-
\*FractionBox[\(A + \((2*Pi*I \((Na + q + 1)\))\)\), \(2\ SNR\)]\), 
          gC]\), 
FractionBox[\(A + 2*Pi*I \((Na + q + 1)\)\), \(2\ SNR\)]]]\)) == 
   10^-10, {Na, Q}]

But it doesn't work? Anyone have any idea about how solving this equation?

Thanks in advance
 
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There are not analytical solutions for all equations. Functions like Solve, Reduce, DSolve, etc. will not always be able to find a solution. In such cases you can only find numerical solutions using e.g. FindRoot.
 
DaleSpam said:
There are not analytical solutions for all equations. Functions like Solve, Reduce, DSolve, etc. will not always be able to find a solution. In such cases you can only find numerical solutions using e.g. FindRoot.

Thanks DaleSpam for replying,

So, you are saying that If I replace the "Solve" command by "FindRoot", I may get a result?

Regards
 
The syntax for FindRoot is a little different than for Solve. You should use the help menu to find the new syntax and some examples.
 
DaleSpam said:
The syntax for FindRoot is a little different than for Solve. You should use the help menu to find the new syntax and some examples.

Ok, I will. Thanks again
 

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