title: Implement 2x2 rotation matrix in c#
body: <p>I rotate a vector using the following code:</p>
  
  <pre><code>   var newVectorX = Math.Cos(step) * normalizedVector.X 
                                   - Math.Sin(step) * normalizedVector.Y;
  
                  var newVectorY = - Math.Sin(step) * (normalizedVector.X )
                                   + Math.Cos(step) * normalizedVector.Y;
  </code></pre>
  
  <p>I tried to create a 2x2 matrix so I just can multiply my normalized vector with the matrix. The result would be the new rotated vector instead the coordinates.</p>
  
  <p><img src="https://i.stack.imgur.com/ISeLM.png" alt="rotation matrix"></p>
  
  <p>Unfortunately <code>System.Windows.Media.Matrix</code> doesn't support 2x2 matrices. I couldn't find any implementation of this rotation matrix so far. How would you implement this?</p>