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empty matrix in solving symbolic equation

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safisay
safisay 2017-11-9
回答： Walter Roberson 2017-11-9
syms k_1 theta1 theta0 M gama l
eqn=(gama*l)/2==(k_1*(sin(theta1) + cos(k_1*(gama - theta1))*sin(theta0) - cos(theta0)*sin(theta1) + cos(theta1)*sin(theta0) - M*sin(theta1) - k_1*sin(k_1*(gama - theta1)) - M*cos(k_1*(gama - theta1))*sin(theta1) + k_1*cos(theta0)*sin(k_1*(gama - theta1)) + M*k_1*sin(k_1*(gama - theta1)) - M*k_1*cos(theta1)*sin(k_1*(gama - theta1))))/(M*(2*k_1 - sin(k_1*(gama - theta1))*sin(theta1) + 2*k_1*cos(k_1*(gama - theta1))*cos(theta1) - k_1^2*sin(k_1*(gama - theta1))*sin(theta1)))
seqn=subs([eqn])
solq=solve(seqn,theta1)
Can anyone please tell me what is wrong with the code because it was giving me empty matrix?
  2 个评论
John D'Errico
John D'Errico 2017-11-9
编辑：John D'Errico 2017-11-9
Why must there be something wrong? Does every problem have an analytical solution? (No.)
The empty result is a signal that it found no analytical solution.
safisay
safisay 2017-11-9
I think there is one or more possible solution of theta1 but the code is not working. don't know why.

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回答（1 个）

Walter Roberson
Walter Roberson 2017-11-9
I ran Maple on this overnight, about 11 hours. Maple got up to 33 gigabytes of memory on it. I had to abend the process to get back control of my machine.
If there is any hope of solving it analytically, it would have to involve some change of variables.

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