title: why XMMatrixInverse() has pDeterminant parameter?
body: <blockquote>
  <pre><code>XMMATRIX XM_CALLCONV XMMatrixInverse(XMVECTOR *pDeterminant, FXMMATRIX M);
  </code></pre>
  </blockquote>
  
  <p>im just beginning to learn directx, i dont understand why this function also asks for determinant param apart from the original matrix itself to calculate the inverse. </p>
  
  <p>from what i remember on the math part the input matrix alone should be sufficient:</p>
  
  <pre><code>orig matrix -&gt; cofactor matrix -&gt; adjoint matrix
  orig matrix -&gt; det[orig matrix]
  inverse = adjoint/det
  </code></pre>
  
  <p>so why does it need the extra parameter? to speed up calculations, eliminate the 2nd step above?</p>