Homework Help: math

Posted by Anonymous on Thursday, April 17, 2008 at 12:34pm.

1) If the sum of the first n terms of a series is Sn where Sn=2n²-n,
(a)prove that the series is an AP, stating the first term and the common difference;
(b)find the sum of the terms from the 3rd to the 12th inclusive

2) In an AP the 6th term is half the 4th term and the 3rd term is 15.
(a)Find the first term and the common difference;
(b)How many terms are needed to give a sum that is less than 65?

Please help

No one has answered this question yet.

Answer this Question

Related Questions

Math - 1) If the sum of the first n terms of a series is Sn where Sn=2n²-n...
pre calc - If Sn represents the sum of the squares of the first n natural ...
math 12 - sequences and series - Given the expression Sn = n^2 + 2n for the sume...
Pre Calc - Write as a series and express as a rational number: 1. 5.36363636...
C++ - Write a MAIN function and a FUNCTION to compute the sum of the below ...
math - thinking/inquiry/problem solving: a formula for the sum of the first n ...
C++ - Write a MAIN function and a FUNCTION to compute the sum of the below ...
C++ - Write a MAIN function and a FUNCTION to compute the sum of the below ...
C++ - you are right the question is exactly like this... can you help me for ...
Arithmetic Series - - Reiny - Consider the series defined by Sn = 3n-1 Find the ...

For Further Reading

First Name:
School Subject:
Answer: