- #1
Sarah00
- 64
- 1
Hi!
If I have a sequence that its first 4 terms are:
30, -31, +32, -32
The pattern is geometric sequence but has alternating signs..
How can I find its sum ..
I know it is composed of 2 sequences ..
However, when I try to separate the 2 sequences .. I get them of different "lengths"
In other words, it is (30+32+34) - (31+33) for 5 terms
but for 4 terms I get:
In other words, it is (30+32) - (31+33)How can I get general formula for both ..
(-1)k helps ! but how! and what about the number of termsThanks!
If I have a sequence that its first 4 terms are:
30, -31, +32, -32
The pattern is geometric sequence but has alternating signs..
How can I find its sum ..
I know it is composed of 2 sequences ..
However, when I try to separate the 2 sequences .. I get them of different "lengths"
In other words, it is (30+32+34) - (31+33) for 5 terms
but for 4 terms I get:
In other words, it is (30+32) - (31+33)How can I get general formula for both ..
(-1)k helps ! but how! and what about the number of termsThanks!