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# Sequences and Series watch

1. I'm a little rusty on these and am attempting this question. Can someone please explain how to go about solving it?

I have to find the 6th term. I imagine I would just substitute 6 into the K's.
2. ?

What are you trying to find?
3. (Original post by JAKstriked)
?

What are you trying to find?
The 6th term, I imagine that its 11 as I substitute 6 into the equation.
4. (Original post by Unknown?)
I'm a little rusty on these and am attempting this question. Can someone please explain how to go about solving it?

a = 2a -1 and I'm given a1= 2
k+1 k

I have to find the 6th term. I imagine I would just substitute 6 into the K's.
use k=1 then
a_2=2a_1-1 ,a_1=2
now use
a_2 you have just found out to find the values of a_3 and a_4.. you need k=5 which will give you the 6th term
5. (Original post by rbnphlp)
use k=1 then
a_2=2a_1-1 ,a_1=2
now use
a_2 you have just found out to find the values of a_3 and a_4.. you need k=5 which will give you the 6th term
I don't quite follow. The text makes it kind of hard to read.
6. (Original post by Unknown?)
I don't quite follow. The text makes it kind of hard to read.
The sequence is recurrent and so to find your you'll need to find a_2, a_3, a_4 and a_5 first.

e.g you know so by your formula. You then need to put a_2 back in to find a_3 and so on.
7. (Original post by Unknown?)
I don't quite follow. The text makes it kind of hard to read.
use k=1 then

now use
a_2 you have just found out to find the values of a_3 and a_4.. you need k=5 which will give you the 6th term so you need the term till a_5
8. Thankyou but now I'm stuck with another question its kind of the opposite of the first question. I have to find the formula of this series.

1, -2, 4, -8, 16, -32
9. (Original post by Unknown?)
Thankyou but now I'm stuck with another question its kind of the opposite of the first question. I have to find the formula of this series.

1, -2, 4, -8, 16, -32
its a sequence
if you look carefully at it you will notice a pattern
pattern
theyre multiplying by -2 each time
10. (Original post by rbnphlp)
its a sequence
if you look carefully at it you will notice a pattern
pattern
theyre multiplying by -2 each time
Yes thankyou I noticed. So the formula is
11. (Original post by Unknown?)
Yes thankyou I noticed. So the formula is

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