title: How to find maximum point of multivariate function in C#
body: <p>Is there any way of finding the maximum point (values of variables) of multivariate function within specific range of variables using open-source resources?</p>
  
  <h2>Background</h2>
  
  <p>I have a code that returns functions, like e.g.:</p>
  
  <p><strong>0.17 - 0.05*x + 0.06*y - 0.02*x^2 + 0.03*x*y + 0.07*x*y^2</strong></p>
  
  <p>Range of each variable is known. Now I just have to find value of every variable at the max point.</p>
  
  <p>I have only found libs that allow me to calculate first derivatives in a specific point of a function (e.g. AutoDiff .NET) but it feels that there has to be an easier way of finding the maximum rather than counting countless derivatives at all possible points.</p>
  
  <h2>Note</h2>
  
  <p>I'm kinda new to c# and programming in general and I've spent great amount of time finding the answer but unfortunately failed. Any suggestions/insights/help are highly welcome.</p>