Câu 9:

Cho hàm số $f\left( x \right) = \left\{ {\begin{array}{*{20}{l}}{\frac{{2\sqrt {x + 2} {\rm{ \;}} - 3}}{{x - 1}}{\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} x \ge 2}\\{{x^2} + 1{\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} x < 2}\end{array}} \right.$. Tính $P = f\left( 2 \right) + f\left( { - 2} \right)$.