题型:解答题 题类:月考试卷 难易度:难
新年份:2020
题型:解答题 题类:月考试卷 难易度:难
新年份:2020
题型:解答题 题类:月考试卷 难易度:难
新年份:2020
已知数列\(\{a _{n} \}\)满足\(a _{n+2} +a _{n} =2a _{n+1} (n∈N ^{*} )\),数列\(\{b _{n} \}\)满足\(\dfrac{{{b}_{n+1}}}{{{b}_{n}}}={{a}_{n+1}}-{{a}_{n}} (n∈N ^{*} )\),且\(a _{1} =b _{1}\),\(a _{3} =5\),\(a _{5} +a _{7} =22\).
\((1)\)求\(a _{n}\)及\(b _{n}\);
\((2)\)令\(c _{n} =a _{n} b _{n}\),\(n∈N ^{*}\),求数列\(\{c _{n} \}\)的前\(n\)项和\(S _{n}\).
题型:解答题 题类:月考试卷 难易度:难
新年份:2020
\(a _{11}\) | \(a _{12}\) | \(…\) | \(a _{1n}\) |
\(a _{21}\) | \(a _{22}\) | \(…\) | \(a _{2n}\) |
\(…\) | \(…\) | \(…\) | \(…\) |
\(a _{n1}\) | \(a _{n2}\) | \(…\) | \(a _{nn}\) |