5.(2023春•长宁区校级期末)将函数f(x)=4cos(π2x)f(x)=4\cos (\frac{\pi }{2}x)f(x)=4cos(2πx)和直线g(x)=x−1g(x)=x-1g(x)=x−1的所有交点从左到右依次记为A1A_{1}A1,A2A_{2}A2,A3A_{3}A3,…\ldots…,AnA_{n}An,若PPP点坐标为(0,3)(0,\sqrt{3})(0,3),则∣PA1→+PA2→+…+PAn→∣=(\vert \overrightarrow{P{A}_{1}}+\overrightarrow{P{A}_{2}}+\ldots +\overrightarrow{P{A}_{n}}\vert =(∣PA1+PA2+…+PAn∣=( )))