Let $\displaystyle{ f(x) = \dfrac{1}{x^2 - 4 x + 6} }$.

1. Find the critical numbers of $f$. (Separate multiple answers by commas. Enter NONE if there are no critical numbers.)
   1. Determine the intervals on which $f$ is increasing and decreasing. interval
      $f$ is increasing on:
      $f$ is decreasing on:
   2. Use the First Derivative Test to determine whether each critical point is a relative maximum, minimum, or neither. (Separate multiple answers by commas. Enter NONE if there no values.)
      Relative maxima occur at $x =$
      Relative minima occur at $x =$