title: How to use fsolve in MATLAB for only one of the variables?
body: <p>I have a function</p>
  
  <pre><code>func(u1,u2,t) 
  </code></pre>
  
  <p>now I want to find the value of u2 when</p>
  
  <pre><code>0 = func(u1, u2, t) 
  </code></pre>
  
  <p>where <code>u1=a</code> and <code>t=b</code> are known values. How can I do this (with <code>fsolve</code> or other functions) in MATLAB? Thanks</p>