Help needed in solving a matrix equation

clear all;

A= [0,1;1,1];

B= [0,1;1,1];

Q= [2,0;0,4];

R= [0.5,0;0,0.25];

syms p11 p12 p21 p22

P = [p11,p12; p21, p22];

eqn = P*A + transpose(A)*P + Q - (P/2)*B*inv(R)*transpose(B)*P - (P/4)*B*inv(R)*transpose(B)*transpose(P) - (transpose(P)/4)*B*inv(R)*transpose(B)*P ==0;

S = solve(eqn);

disp(P);

I want to find the solution of P matrix, I am kind of new to MATLAB. Any kind of help is appreciated.

Answer 1

[Jan]

A= [0,1;1,1];
B= [0,1;1,1];
Q= [2,0;0,4];
R= [0.5,0;0,0.25];
syms p11 p12 p21 p22
P = [p11, p12; p21, p22];
eqn = P * A + A.' * P + Q  - (P/2) * B * inv(R) * B.' * P - ...
      (P/4) * B * inv(R) * B.' * P.' - (P.' / 4) * B * inv(R) * B.' *P  == 0;
S = solve(eqn);
S.p11

ans = 

The same for the other components. So you did calculate your solution already, but display the input P instead of the output S.

[VUTNOORI VAMSHI]

Thanks for the answer !