Alright so my teacher decides to give us this problem with minimal instruction, and my book is awful.
Fiven the following sequence 8,14,20,26
Find the nth term
Find sn(phoenetically sounds S sub n )
Prove your formula works for all n
Alright so my teacher decides to give us this problem with minimal instruction, and my book is awful.
Fiven the following sequence 8,14,20,26
Find the nth term
Find sn(phoenetically sounds S sub n )
Prove your formula works for all n
Instead of writing out answers i will nearly work out by giving hints
Find the nth term:
Mathstud28 already gave you the answer (assuming n starts from 0)
If you know arithmetic progressions, the series you have is an A.P with first term '8' and common difference '6'.
So $\displaystyle T_n = a+(n-1)d = 8+6(n-1) = 6n+2$
Find sn(phoenetically sounds S sub n )
$\displaystyle S_n = \sum (6n+2) = \sum 6n+ \sum 2 = 3n(n+1) + 2n = 3n^2 +5n$