How to pick an answer from solver for further calculations

Hi there!

I would be appreciated if someone could help me about following codes.

syms Xi  

%Feed Stoichiometry
yCO  = 0.15;
yCO2 = 0.1;
yH2  = 0.45;
yH2O = 0.30;

%Equilibrium

eqn = ((yCO2 + Xi) * (yH2 + Xi) / (yCO - Xi) * (yH2O - Xi));
S = solve(eqn - K == 0, Xi)
 Xi = vpa(S)

Here, I get 3 different answers and I would like to pick the one between 0 and 1 (for any value of K) to do further calculations. For K = 1.3440e+04, answer values are below.

 Xi =
 
  0.1499983259199154580821882262029
  115.73248002820162922028599235038
 -116.13247835412154467836818057659

Answer 1

[darova]

Use logical operators

ix = 0<Xi && Xi<1;
x1 = Xi(ix);

[Hazal]

Thank you!

It worked.