How to obtain matrix components

Hi All,

I am new to Matlab, and I'd like to obtain the following values: EL,VLT,VTL, and GLT from

x=[Q11 Q12 0;

Q12 Q22 0;

0 0 Q66]

the x is given equal to: =[20 0.7 0;

0.7 2 0;

0 0 0.7];

I have been trying with solve as indicated below, however, 0*1 sym is the result of each component: also maybe I should try to use subs, function but nothing working unfortunely

clear all;

clc;

close all;

syms EL vlt vtl ET GLT;

y=[EL/1-vlt*vtl vlt*ET/1-vlt*vtl 0;vlt*ET/1-vlt*vtl ET/1-vlt*vtl 0;0 0 GLT]==[20 0.7 0;0.7 2 0;0 0 0.7];

z= solve(y,EL,vlt,vtl,ET,GLT);

Answer 1

[Star Strider]

You need to enclose the variables you are solving for in square brackets:

[EL,vlt,vtl,ET,GLT] = solve(y,[EL,vlt,vtl,ET,GLT]);

returning:

EL =
19
 
vlt =
-3/10
 
vtl =
10/3
 
ET =
1
 
GLT =
7/10

As desired.

Answer 2

[Ali Tawfik]

Hi Star, it's working, but I am not sure if the answer is correct releavant to the equations. But anyway thank you very much for your help!

[Star Strider]

As always, my pleasure!