题型:解答题 题类:其他 难易度:难
年份:2018
已知\(\left(1+x\right){2}^{n+1}={a}_{0}+{a}_{1}x+{a}_{2}{x}^{2}+…+{a}_{2n+1}{x}^{2n+1} \),\(n\in {{\mathbf{N}}^{*}}.\)记\({{T}_{n}}=\sum\limits_{k=0}^{n}{(\ 2k+1\ ){{a}_{n-k}}}\).
\((1)\)求\(T_{2}\)的值;
\((2)\)化简\({{T}_{n}}\)的表达式,并证明:对任意的\(n\in {{\mathbf{N}}^{*}}\),\({{T}_{n}}\)都能被\(4n+2\)整除.
题型:解答题 题类:其他 难易度:难
年份:2018
设\((1-x)^{n}=a_{0}+a_{1}x+a_{2}x^{2}+…+a_{n}x^{n}\),\(n∈N^{*}\),\(n\geqslant 2\).
\((1)\)设\(n=11\),求\(|a_{6}|+|a_{7}|+|a_{8}|+|a_{9}|+|a_{10}|+|a_{11}|\)的值;
\((2)\)设\(b_{k}= \dfrac{k+1}{n-k}a_{k+1}(k∈N,k\leqslant n-1)\),\(S_{m}=b_{0}+b_{1}+b_{2}+…+b_{m}(m∈N,m\leqslant n-1)\),求\(\left| \left. \dfrac{S_{m}}{C\rlap{^{m}}{_{n-1}}} \right. \right|\)的值.