百度试题 结果1 题目Find the sum of the arithmetic sequence.∑_(i=1)^∑(2i-3) 相关知识点: 试题来源: 解析 =3601a_1=2(1)-3=-1 a_(20)=2(20)-3=37 20 反馈 收藏
The sum, s, of the arithmetic series a1+a2+⋯+an is given by the formula s=n(a1+an2) where n is the number of terms, a1 is the first term of the series, and an is last term of the series. Answer and Explanation: Let's expand the given series. {eq}\begin{align...
Finding the Sum of Arithmetic Sequence: An arithmetic sequence is a set of numbers in which the difference between consecutive terms is constant. The sum of an arithmetic sequence is calculated by using the formula given below: {eq}{S_n} = \dfrac{n}{2}\left[ {2{a_1} + ...
Find the sum of the first 20 terms of the arithmetic sequence where the first term is 3 and the common difference is 4. A. 780 B. 790 C. 800 D. 810 相关知识点: 试题来源: 解析 C。解析:使用等差数列求和公式 Sn = n(a1 + an)/2,先求出第 20 项为 79,再计算可得和为 800。
This is theformulato find thesumof the firstnntermsof thesequence. Toevaluateit, the values of the first andnnthtermsmust be found. Sn=n2⋅(a1+an)Sn=n2⋅(a1+an) This is anarithmetic sequencesince there is a commondifferencebetween eachterm. In this case, adding22to the previoustermi...
百度试题 结果1 题目Find the nth term of each arithmetic sequence described.a_1=10,d=-5,n=21 相关知识点: 试题来源: 解析 —90 反馈 收藏
Find the sum to n terms of the series given below:-52+62+72+...+202 View Solution Exams IIT JEE NEET UP Board Bihar Board CBSE Free Textbook Solutions KC Sinha Solutions for Maths Cengage Solutions for Maths DC Pandey Solutions for Physics ...
An infinite series is the sum of terms in an infinitely long sequence, but taking the sum of terms in a finite portion of the sequence is called a partial sum. Explore these two concepts through examples of five types of series: arithmetic, geometric, harmonic, alte...
The correct Answer is:49[109(10n−1)−n] To find the sum of the first n terms of the series 4+44+444+…, we can follow these steps: Step 1: Identify the pattern in the seriesThe terms can be expressed as:- 1st term: 4- 2nd term: 44=4×11- 3rd term: 444=4×111 We ...
Problem, the sequence is either arithmetic or geometric. (A) Find a formula for the nth term of each sequence. (B) Find the nth term. (C) Find the sum of the first n terms of the sequence.-2, 1, 4, 7, 7 相关知识点: