\[y = x^{2}e^{- x};\ \ \ \ \ x_{0} = 1:\]
\[y^{'}(x) = \left( x^{2} \right)^{'} \bullet e^{- x} + x^{2} \bullet \left( e^{- x} \right)^{'} =\]
\[= 2x \bullet e^{- x} + x^{2} \bullet \left( - e^{- x} \right) =\]
\[= xe^{- x} \bullet (2 - x).\]
\[tg\ a = y^{'}(1) = e^{- 1} \bullet (2 - 1) = \frac{1}{e}.\]
\[Ответ:\ \ tg\ a = \frac{1}{e}.\]