$f\left( x \right) = \left\{ \matrix{ {{{x^2} - 2} \over {x - \sqrt 2 }},\,{\rm{ nếu }}\,\,x \ne \sqrt 2 \hfill \cr  2\sqrt 2 {\rm{ , \,\,nếu }}\,\,x = \sqrt 2 \hfill \cr} \right.$

$g\left( x \right) = \left\{ \matrix{ {{1 - x} \over {{{\left( {x - 2} \right)}^2}}},\,\,{\rm{ nếu }}\,\,x \ne 2 \hfill \cr  3{\rm{ ,\,\, nếu }}\,\,x = 2 \hfill \cr} \right.$