Cho hàm số $$f\left( x \right)=\left\{ \begin{array}{*{35}{l}}\frac{2\sqrt{x+2}-3}{x-1} & x\ge 2  \\   {{x}^{2}}\text{+1} & x\end{array} \right.$$. Tính $$P=f\left( 2 \right)+f\left( -2 \right)$$.