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 Author Comment/Response Bill Simpson 07/08/13 4:56pm Solve is terrible with trig problems, Reduce is better, but only with exact problems. Change approximate numbers to exact, Change pi to Pi, Simplify the system of equations, Replace \[Theta]2 with \[Theta]1, Use Reduce instead of Solve In[1]:= \[Rho]0 = 127/100; p0 = 1013*10^2; p1 = 3*p0; \[Gamma] = 14/10; \[Phi]1 = 30*(Pi/180); sys = Simplify[{ \[Rho]0*u0*Sin[\[Phi]1] == \[Rho]1*u1* Sin[\[Phi]1 - \[Theta]1], p0 + \[Rho]0*(u0*Sin[\[Phi]1])^2 == p1 + \[Rho]1*(u1*Sin[\[Phi]1 - \[Theta]1])^2, \[Rho]0*Tan[\[Phi]1] == \[Rho]1*Tan[\[Phi]1 - \[Theta]1], \[Gamma]*(p0/((\[Gamma] - 1)*\[Rho]0)) + (1/2)*(u0*Sin[\[Phi]1])^2 == \[Gamma]*(p1/((\[Gamma] - 1)*\[Rho]1)) + (1/2)*(u1*Sin[\[Phi]1 - \[Theta]1])^2, \[Rho]1*u1*Sin[\[Phi]2] == \[Rho]2*u2*Sin[\[Phi]2 - \[Theta]2], p1 + \[Rho]1*(u1*Sin[\[Phi]2])^2 == p2 + \[Rho]2*(u2*Sin[\[Phi]2 - \[Theta]2])^2, \[Rho]1*Tan[\[Phi]2] == \[Rho]2*Tan[\[Phi]2 - \[Theta]2], \[Gamma]*(p1/((\[Gamma] - 1)*\[Rho]1)) + (1/2)*(u1*Sin[\[Phi]2])^2 == \[Gamma]*(p2/((\[Gamma] - 1)*\[Rho]2)) + (1/2)*(u2*Sin[\[Phi]2 - \[Theta]2])^2}] Out[6]= {127 u0 == 200 u1 \[Rho]1 Sin[1/6 (\[Pi] - 6 \[Theta]1)], 127 u0^2 == 400 (202600 + u1^2 \[Rho]1 Sin[1/6 (\[Pi] - 6 \[Theta]1)]^2), 300 \[Rho]1 Tan[1/6 (\[Pi] - 6 \[Theta]1)] == 127 Sqrt[3], 127 u0^2 + (2836400 (-381 + 100 \[Rho]1))/\[Rho]1 == 508 u1^2 Sin[1/6 (\[Pi] - 6 \[Theta]1)]^2, u2 \[Rho]2 Sin[\[Theta]2 - \[Phi]2] + u1 \[Rho]1 Sin[\[Phi]2] == 0, p2 + u2^2 \[Rho]2 Sin[\[Theta]2 - \[Phi]2]^2 == 303900 + u1^2 \[Rho]1 Sin[\[Phi]2]^2, \[Rho]2 Tan[\[Theta]2 - \[Phi]2] + \ \[Rho]1 Tan[\[Phi]2] == 0, (7 p2)/\[Rho]2 + u2^2 Sin[\[Theta]2 - \[Phi]2]^2 == 2127300/\[Rho]1 + u1^2 Sin[\[Phi]2]^2} In[7]:= Reduce[sys, {\[Rho]1, u0, u1, \[Theta]1, \[Rho]2, u2, p2, phi2}] Out[7]= ...LargeComplicatedResultAfterAFewSeconds... Study that and see what you can discover. Simplify may or may not help with parts of that. URL: ,

 Subject (listing for 'Solve nonlinear algberic euations') Author Date Posted Solve nonlinear algberic euations Ritwik Ghoshal 07/08/13 05:25am Re: Solve nonlinear algberic euations Bill Simpson 07/08/13 4:56pm Re: Re: Solve nonlinear algberic euations Ritwik Ghoshal 07/10/13 02:03am Re: Re: Re: Solve nonlinear algberic euations Bill Simpson 07/10/13 4:35pm
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