Sn=(n+1)(a1+an)/2 D. Sn=(n-1)(a1+an)/2 相关知识点: 试题来源: 解析 A。本题考查等差数列求和公式。选项 A 中 Sn 表示前 n 项和,n 是项数,a1 是首项,an 是末项。除以 2 是因为求和时首尾相加乘以项数再除以 2。选项 B 不是等差数列求和公式,选项 C 和 D 也不正确。反馈 收藏 ...
The formula for the sum of an arithmetic sequence is S = n(a₁ + aₙ)/2. What does n represent? A. The number of terms in the sequence. B. The common difference. C. The first term. D. The last term. 相关知识点:
The formula for the sum of an arithmetic sequence is S = n(a₁ + an)/2 (where n is the number of terms, a₁ is the first term and an is the nth term). If n = 10, a₁ = 2 and an = 18, what is the value of S?
Formula for Arithmetic Series The Simple Arithmetic Sequences Let's say we have the simplest of arithmetic sequences. {1,2,3,⋅⋅⋅,n}{1,2,3,⋅⋅⋅,n} And what I want to think about is what is the sum of this sequence going to be? And the sum of a sequence, we ...
The recursive formula for an arithmetic sequence whose common difference is denoted as {eq}d. {/eq} $$a_{n} = a_{n-1}+d $$ Answer and Explanation:1 Given arithmetic sequence $$1,15,29,43,... $$ here the first term and the...
The recursive formula for an arithmetic sequence is:\(a_1=-8a_n=a_(n-1)+3.What is the 3rd term in the sequence?OA.-5O B. -14OC.-24O D.-2 相关知识点: 试题来源: 解析 a_1=-8 a_n=a_(n-1)+3 n=2then a_2=a_2+3 =a_1+3 =—8+3 a2=—5 n-3 then a_3=a_2+...
A. the first term B. the number of terms C. the common difference D. the \(n\)th term 相关知识点: 试题来源: 解析 C。中文解析:根据文章内容,公式中\(d\)是 common difference(公差)。反馈 收藏
A. \(na_1\) B. \(\frac{n}{2}(a_1 + a_n)\) C. \(n(a_1 + a_n)\) D. \(\frac{n}{2}a_1\) 相关知识点: 试题来源: 解析 B。中文解析:文章中给出等差数列前\(n\)项和公式为\(S_n=\frac{n}{2}(a_1 + a_n)\)。反馈 收藏 ...
Find the formula for the nth term, and find the indicated term for each arithmetic sequence.a) 3, 5, 7, ; t_(30)b) -2, -6, -10, ; t_(25)c) -4, 3, 10, ; t_(18) 相关知识点: 试题来源: 解析 a) The n^((th)) term and value of t_(30) are 2n+1 and 61 ...
百度试题 结果1 题目Find a formula for the nth term of the arithmetic sequence a_3=16, a_4=20 相关知识点: 试题来源: 解析 a_n=4n+4 反馈 收藏