2. As shown in Figure 9, the side length of square $ABCD$ is 1, and point $P$ is any point on $BC$ (it can coincide with point $B$ or point $C$). Perpendiculars are drawn from $B$, $C$, and $D$ to the ray $AP$, with the feet of the perpendiculars being $B'$, $C'$, and $D'$, respectively. The maximum value of $BB' + CC' + DD'$ is $\qquad$, and the minimum value is $\qquad$ (15th Jiangsu Province Junior High School Mathematics Competition)
( Hint: Consider point $P$ at extreme positions $B$ and $C$. Answer: $2$, $\sqrt{2}$. )