I've attached the problem I'm stuck on, I tried using the formula for geometric series several times but I'm guessing that because there are two terms I should be going about it a different way? Could someone help me out?
Hello, fattydq!
Find the sum of the series if it converges: .
... but I'm guessing that because there are two terms ... . . What two terms?
We have: .
This is an infinite geometric series with first term and common ratio
Its sum is: .
~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
That second problem is interesting . . .
We have: .
And the series is: .
This too is an infinite geometric series,
. . but since , the series diverges.