Write the Word or Phrase That Best Completes Each Statement $$R ( x ) = \frac { x ^ { 3 } - x ^ { 2 } + x - 1 } { x ^ { 4 } - x ^ { 3 } + 3 x - 3 }$$

Essay

Write the word or phrase that best completes each statement or answers the question.
Determine where the rational function is undefined. Determine whether an asymptote of a hole appears at such numbers.
- $$R ( x ) = \frac { x ^ { 3 } - x ^ { 2 } + x - 1 } { x ^ { 4 } - x ^ { 3 } + 3 x - 3 }$$