6.
\((1)\)已知\(p:(a+1)(a-2)\geqslant 0\),\(q:1 < a < 3\),若\(q\)为真命题,\(p\wedge q\)为假命题,则实数\(a\)的取值范围是_____________.
\((2)\)在空间四边形\(ABCD\)中,\(AB=CD\)且\(AB\)与\(CD\)所成的角为\({{30}^{o}}\),\(E\),\(F\)分别为\(BC,AD\)的中点,则\(EF\)与\(AB\)所成角的大小为_____.
\((3)\)正方体\(ABCD{-}{{A}_{{1}}}{{B}_{{1}}}{{C}_{{1}}}{{D}_{{1}}}\)的棱长为\(1\),点\(M\)是面对角线\(A{}_{{1}}B\)上的动点,则\(AM+M{{D}_{1}}\)的最小值为_________.
\((4)\)如图,\({{F}_{1}},{{F}_{2}}\)是椭圆\({{C}_{1}}:\dfrac{{{x}^{2}}}{4}+{{y}^{2}}=1\)与双曲线\({{C}_{2}}\)的公共焦点,\(A,B\)分别是\({{C}_{1}},{{C}_{2}}\)在第二,第四象限的公共点,若四边形\(A{{F}_{1}}B{{F}_{2}}\)为矩形,则\({{C}_{2}}\)的离心率是______.