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 Author Comment/Response Mayank Sahni 03/25/01 9:54pm i'm new to mathematica and i'm having considerable difficulty solving the following problem.can someone please help me out and tell me what i'm doing wrong here.I want to plot S v/s B and also q_s v/s B for various values of B. n,F,S all involve q_s and B therefore the p.d's have to be solved simultaneously Da = 0.1 Le = 1 g = 20 ord = 1 q = 0 x = 0 sol1 = DSolve[{ n = (3*phi*Coth[3*phi] - 1)/(3*phi^2), phi = Sqrt[Exp[q_s/(1 + q_s/g)]], D[F[q_s, phi, B], q_s] + (q_s - q)*(1/n)*D[n[q_s, phi, B], q_s] = 1 - (q_s - q)*{1/((1 + q_s/g)^2) - {(ord*Le/B)/(1 - x - (Le/B)*(q_s - q))}}, D[F[q_s, phi, B], B] = -(q_s - q)*(1/ B + (1/n)*(D[n[q_s, phi, B], B]) - {(ord*Le*(q_s - q)/B^2)/(1 - x - (Le/B)*(q_s - q))}), D[n[q_s, phi, B], phi] = {(9*phi^2 + 2 - 3*phi*Coth[3*phi][1 + 3*p*Coth[3*phi]])/(3* phi^3)}, D[n[q_s, phi, B], q_s] = D[n[q_s, phi, B], phi]*(phi/ 2)*{1/((1 + q_s/g)^2) - {((ord - 1)*Le/B)/(1 - x - (Le/B)*(q_s - q))}}, D[n[q_s, phi, B], B] = 0, F[q_s] = (q_s - q) - (B*Da/Le)* Exp[q_s/(1 + q_s/g)]*(1 - x - (Le/B)*(q_s - q))*n = 0, S = -{(B/q_s)*(D[F[q_s, phi, B], B]/D[F[q_s, phi, B], q_s])},}] Plot[Evaluate[{S} /. sol1, {q_s} /. sol1], {B}] URL: ,

 Subject (listing for 'Partial differential equations') Author Date Posted Partial differential equations Mayank Sahni 03/25/01 9:54pm Re: Partial differential equations Henry Lamb 03/28/01 3:00pm
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