title: How to solve this constrained nonlinear system of equations for positive values?
body: <p>How can I solve this system for positive values of x?
  I used fval but it can't find the answer and asks for larger iterations which is unhelpful...<br>
    <strong>a must be positive and smaller than 0.05<br>
  b must be larger than 88</strong> </p>
  
  <pre><code>function F = Final_Project_2(x)
   F = [(1/x(1)) + (1/x(2))- (2/(7*x(3)));
         (x(3)+2*x(4))*(15*x(2))/((x(1)+x(2))*x(3)-0.7/x(3))-14;
         (x(3)*((0.576*x(2)/(x(1)+x(2))*x(3)) - 0.27/x(3)))/(x(3)+(0.576*x(2)/(x(1)+x(2))*x(3)) - 0.27/x(3)) - a;
         ((0.576*x(2)*x(3)/(x(1)+x(2))*x(3)) - 0.27*x(4)/x(3))-b];
  </code></pre>
  
  <p><strong>Edit:</strong>
  How this question is "too localized"?!!<br>
  I derived this system of equations from designing a Common Emitter Amplifier. First equation is came from independency from $/betha /$. Second one is kvl from Collector to Emitter. Third one is the CE gain.Last one is R_in</p>