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# ComplexExpand_NSolve_Problem

Posted 10 years ago
 Hello, I am facing problem in ComplexExpand with NSolve for 3 variables, as shown in the attached file. Please suggest me . thanks Attachments:
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Posted 10 years ago
 Hello Sir,As you suggested the command , that was really helpful for me but now again facing problem in the case of 5-variables, please see the file in attachment. When i run the file for the case of system of 5 equations with 5 variables, my system gets stuck and stop working, please suggest me.Thanks Attachments:
Posted 10 years ago
 It's probably outside what NSolve methods can handle. Might try using FindRoot or FindMinimum of a sum of squares to get isolated real roots.
Posted 10 years ago
 Thanks Sir ,Your suggestion is really useful and it worked well for my Case.Once again Thanks a lot
Posted 10 years ago
 I am not able to replicate the problem, at least in Mathematica 10.0.2. exp1 = ComplexExpand[ Im[(1 + I)/(2 + 3 I - bb) + (1 + I)/(2 + 3 I - cc)] + Im[(1 + I)/(2 + 3 I - dd)]] - 3.5; exp2 = ComplexExpand[ Im[(2 + 2 I)/(3 + 4 I - bb) + (2 + 2 I)/(3 + 4 I - cc)] + Im[(2 + 2 I)/(3 + 4 I - dd)]] - 0.75; exp3 = ComplexExpand[ Im[(3 + 3 I)/(5 + 7 I - bb) + (3 + 3 I)/(5 + 7 I - cc)] + Im[(3 + 3 I)/(5 + 7 I - dd)]] - 0.75; eq5s = {exp1, exp2, exp3}; varr2 = {bb, cc, dd}; Timing[solns = NSolve[eq5s, varr2];] (* Out[20]= {2.727674, Null} *) In[21]:= Length[solns] (* Out[21]= 48 *) Earlier versions used a different mathod and may be slower. One thing that works in version 9 is to clear denominators. polys = Numerator[Together[eq5s]] Now NSolve[polys, varr2] will be quite fast.
Posted 10 years ago
 It looks like there are too many solutions for NSolve to enumerate. Possibly reformulate the problem using FindRoot. You then have to provide rough estimates for the 3 vector solutions.