MATLAB: Solve not returning two answers

solve

Hi,
I have a nonlinear equation that I need to sovle for 'x'. Following is my code:
syms x q N 
q=.95;
N=500;
eqn = 2*log((((N-x)/(q*N))^(N-x))*((x/((1-q)*N))^x)) == 3.841;
solx = solve(eqn, x);
I am expecting two values for 'x' but am getting just one (i.e. ~35). I am not getting the other value of 16. Also I get the following warning:
Warning: Cannot solve symbolically. Returning a numeric approximation instead.
Please tell me what I am doing wrong.
Thanks,

Best Answer

Hello,
Maybe you could try with another approach, for example, 
eq = @(y)2*log((((N-y)./(q*N)).^(N-y)).*((y./((1-q)*N)).^y)) - 3.841;
fsolve(eq,[0 100])
It will give two solutions. 
ans =
   16.0510   35.1056
But in this case, you should be aware that if you chose different interval of solutions, for example [-100, 100] in fsolve, you may get wrong results.
Related Question