6.
\((1)\)计算\( \dfrac{1-i}{(1+i{)}^{2}}+ \dfrac{1+i}{(1-i{)}^{2}}= \)_____________
\((2)\)已知\(F\)是抛物线\(y\)\({\,\!}^{2}=\)\(x\)的焦点,\(A,B\)是该抛物线上的两点,\(\left| AF \right|+\left| BF \right|=3\),则线段\(AB\)的中点到\(y\)轴的距离为 \(.\)
\((3)\)观察下列不等式:
\(1+\dfrac{1}{{{2}^{2}}} < \dfrac{3}{2}\),
\(1+\dfrac{1}{{{2}^{2}}} +\dfrac{1}{{{3}^{2}}} < \dfrac{5}{3}\),
\(1+\dfrac{1}{{{2}^{2}}} +\dfrac{1}{{{3}^{2}}} +\dfrac{1}{{{4}^{2}}} < \dfrac{7}{4}\),
\(……\)
照此规律,第六个不等式为 .
\((4)\)有下列命题:
\(①\)设集合\(M\)\(=\{\)\(x\)\(|0 < \)\(x\)\(\leqslant 3\}\),\(N\)\(=\{\)\(x\)\(|0 < \)\(x\)\(\leqslant 2\}\),则“\(a\)\(∈\)\(M\)”是“\(a\)\(∈N\)”的充分而不必要条件;
\(②\)命题:“若\(a\)\(∈\)\(M\),则\(b\notin M\)”的逆否命题是:若\(b\)\(∈\)\(M\),则\(a\notin M\);
\(③\)若\(p\)\(∧\)\(q\)是假命题,则\(p\)、\(q\)都是假命题;
\(④\)命题\(P\):“\(\exists \) \(x\)\({\,\!}_{0}∈R\),\(x\)\(\rlap{{\!\,}^{2}}{{\!\,}_{0}}-\)\(x\)\({\,\!}_{0}-1 > 0\)”的否定\(\neg \) \(P\):“\(\forall \) \(x\)\(∈R\),\(x\)\({\,\!}^{2}-\)\(x\)\(-1\leqslant 0\)”.
其中真命题的序号是________.