# Thread: Math 10- Arithmetic Series

1. ## Math 10- Arithmetic Series

Hello,

My first time trying this site out-- and in desperate need of help. I'd like not for the answer to be provided but just which formulas to use

Q: Consider the series defined by Sn= 3n *2- n
a) Find the first four terms of the series
b) Determine the eighth term of the corresponding sequence.

*meant to be n squared

2. Originally Posted by Judy
Hello,

My first time trying this site out-- and in desperate need of help. I'd like not for the answer to be provided but just which formulas to use

Q: Consider the series defined by Sn= 3n *2- n
a) Find the first four terms of the series
what problem are you having with this question exactly? the first four terms of the series are $S_1, S_2,S_3 \mbox { and } S_4$

so for the first term, you plug in n = 1 into the formula above, for the second plug in n = 2, etc

b) Determine the eighth term of the corresponding sequence.
now this one is a little harder, but the answer to the last question helps us out. The first term of the corresponding sequence is $S_1$, the second term is $S_2 - S_1$, the third term is $S_3 - S_2$ and so on.

questions: why is that? do you know the difference between a sequence and a series? can you do the question now that you know all this information?

*meant to be n squared
if you can't use LaTex, use "^" to represent powers. so you would type S_N = 3n^2 - n

3. Hi, Thank You! For the first question I guess i was over complicating it, I figured there had to be more involved. Thx again and for the ^tip!

4. Originally Posted by Judy
Hi, Thank You! For the first question I guess i was over complicating it, I figured there had to be more involved. Thx again and for the ^tip!