How do I use the solve command
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I am trying to solve for a certain M that will satisfy 2 equations using the solve command. I know my final answer is supposed to be 1.2, and I have defined my equations. I am not sure if I am incorrectly using the solve command or have incorrectly defined the equations.
r = 1.4;
rm1 = r-1;
rp1 = r+1;
syms M
A_AS=sqrt((1/M^2)*(((2+rm1*M^2)/rp1)^(rp1/rm1)));
Po2_Po1=((rm1*.5*M^2)/(1+rm1*.5*M^2))^(r/rm1)*(1/(((2*r)/rp1)*M^2-(rm1/rp1)))^(1/rm1);
Ac_At = A_AS*Po2_Po1 == 1.2;
M = solve(Ac_At,M)
I would appreciate the help, thank you for your time
2 个评论
Walter Roberson
2018-3-15
MATLAB is finding one of the roots but not all of the roots.
For that those equations, are two real roots:
temp = roots([3630287, 15558480, -12224520, 3598560, -521640, 37584, -1080]);
temp(imag(temp)~=0) = [];
temp(temp<0) = [];
sol = sqrt(temp);
along with the negative of that. Approximately +/- 0.386916692037127
We do not know if your equations are right...
Jose Camorlinga Medina
2018-3-15
编辑：Walter Roberson
2018-3-15
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2018-3-15
2018-3-15
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