\((1)\)分解因式:\(a{{x}^{2}}-6axy+9a{{y}^{2}}= \)____________________________
\((2)\)化简:\((a+2+\dfrac{5}{2-a})\cdot \dfrac{2a-4}{a+3}= \)________________
\((3)\)如图,在平面直角坐标系中,经过点\(A\)的双曲线\(y=\dfrac{k}{x}(k > 0)\)同时经过点\(B\),且点\(A\)在点\(B\)的左侧,点\(A\)的横坐标为\(\sqrt{2}\),\(∠AOB=∠OBA=45^{\circ}\),则\(k\)的值为_____
\((4)\)如图,已知\(P\)是正方形\(ABCD\)外一点,且\(PA=3\),\(PB=4\) ,则\(PC\)的最大值是_______
\((5)\)如图,一段抛物线:\(y=-{{x}^{2}}+2x(0\leqslant x\leqslant 2)\) 记为 \(C_{1}\) ,它与\(x\)轴交于两点\(O\)、\(A_{1}\);将\(C_{1}\)绕\(A_{1}\)旋转\(180^{\circ}\)得到\(C_{2}\),交\(x\)轴\(A_{2}\);将\(C_{2}\)绕\(A_{2}\)旋转\(180^{\circ}\)得到\(C_{3}\),交\(x\)轴于\(A_{3}\);\(…\)如此进行下去,直至得到\(C\)\({\,\!}_{6}\),若点\(P(11,m)\)在第\(6\)段抛物线\(C\)\({\,\!}_{6}\)上,则\(m=\)________