Question

Check my answer?
Find S12 for the series 2 + 5 + 8 +...

I think it's 35

Answer 1

S12 means "the 12th partial sum". It's a lot bigger than 35

Answer 2

Can you explain how to do it please?

Answer 3

what is the nth term equal to

Answer 4

2?

Answer 5

the nth term will be some expression with n in it

Answer 6

okay is it 2n then? I'm sorry I'm confused on the section I'm doing.

Answer 7

first term is a1 = 2
common difference is d = 3

you plug those things into an = a1 + d(n-1) to get the nth term

Answer 8

okay I got n=1? I feel like I somehow did something wrong in that equation lol

Answer 9

\[\Large a_{n} = a_1 + d(n-1)\]

\[\Large a_{n} = 2 + 3(n-1)\]

\[\Large a_{n} = ???\]

Answer 10

okay thank you I understand the equation now

Answer 11

so that simplifies to what?