1.
已知椭圆\(\Gamma \):\(\dfrac{{{x}^{2}}}{4}+\dfrac{{{y}^{2}}}{2}=1\),过点\(P(1,1)\)作倾斜角互补的两条不同直线\({{l}_{1}}\),\({{l}_{2}}\),设\({{l}_{1}}\)与椭圆\(\Gamma \)交于\(A\)、\(B\)两点,\({{l}_{2}}\)与椭圆\(\Gamma \)交于\(C\),\(D\)两点.
\((1)\)若\(P(1,1)\)为线段\(AB\)的中点,求直线\(AB\)的方程;
\((2)\)记\(\lambda =\dfrac{\left| AB \right|}{\left| CD \right|}\),求\(\lambda \)的取值范围.