\[y = \frac{x^{3} - 2x^{2} + x - 2}{x^{2} + 1} =\]
\[= \frac{x^{2}(x - 2) + (x - 2)}{x^{2} + 1} =\]
\[= \frac{(x - 2)\left( x^{2} + 1 \right)}{x^{2} + 1} =\]
\[= x - 2 \Longrightarrow линейная\ функция.\]