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Can anybody help me with the following code for solving a system of nonlinear recurrence equations. When I evaluate the kernel and run it, the output is the same is my input as if the Mathematica is unable to solve it.

Rs = 0.3; Ls = 8.2*10^-3; pm = 0.125; p = 3; Tl = 12; J = 0.004; B = 0.001; Ts = 25*10^-6;

RSolveValue[{isd[k + 1] == (1 - (Rs*Ts)/Ls)*isd[k] + Ts*wr[k]*isq[k] + Ts/Ls*100,
isq[k + 1] == (1 - (Rs*Ts)/Ls)*isq[k] - Ts*wr[k]*isd[k] - pm*wr[k]*Ts/Ls + Ts/Ls*100,
wr[k + 1] == (1 - (B*Ts)/J)*wr[k] + (p*Ts)/J (1.5*p*pm*isq[k] - Tl),
th[k + 1] == th[k] + Ts*wr[k],
isd[0] == 0, isq[0] == 0, wr[0] == 0, th[0] == 0}, {isd,isq,wr,th}, k]
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    $\begingroup$ It seems that the presence of quadratics takes it outside the capabilities of RSolve. Offhand I do not know if any methods exist that handle such cases. $\endgroup$ – Daniel Lichtblau Nov 12 '18 at 16:35
  • $\begingroup$ You can solve numerically by using RecurrenceTable? $\endgroup$ – Mariusz Iwaniuk Nov 12 '18 at 19:40

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