For all of the matches below, x=c\displaystyle {x}={c} is a critical number of f\displaystyle {f}.
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  1. f\displaystyle {f} has a local minimum at (c,f(c))\displaystyle {\left({c},{f{{\left({c}\right)}}}\right)}.
  2. f\displaystyle {f} has a local maximum at (c,f(c))\displaystyle {\left({c},{f{{\left({c}\right)}}}\right)}.
  3. (c,f(c))\displaystyle {\left({c},{f{{\left({c}\right)}}}\right)} is neither a local maximum nor a local minimum.