12. Given the function $f ( x ) = \left\{ \begin{array} { l } x ^ { 2 } , x \leq 1 \\ x + \frac { 6 } { x } - 6 , x > 1 \end{array} \right.$ , then $f [ f ( - 2 ) ] =$ $\_\_\_\_$ , and the minimum value of $f ( x )$ is $\_\_\_\_$.
12. Given the function $f ( x ) = \left\{ \begin{array} { l } x ^ { 2 } , x \leq 1 \\ x + \frac { 6 } { x } - 6 , x > 1 \end{array} \right.$ , then $f [ f ( - 2 ) ] =$ $\_\_\_\_$ , and the minimum value of $f ( x )$ is $\_\_\_\_$.\\