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

    a_{k+1}=2a_k-1
    I have to find the 6th term. I imagine I would just substitute 6 into the K's.
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    a_{k+1}=2a_k-1 ?

    What are you trying to find?
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    (Original post by JAKstriked)
    a_{k+1}=2a_k-1 ?

    What are you trying to find?
    The 6th term, I imagine that its 11 as I substitute 6 into the equation.
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    (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
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    (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.
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    (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 a_6 you'll need to find a_2, a_3, a_4 and a_5 first.

    e.g you know a_1 so a_2=2a_1-2 by your formula. You then need to put a_2 back in to find a_3 and so on.
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    (Original post by Unknown?)
    I don't quite follow. The text makes it kind of hard to read.
    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 a_{5+1}=2a_5-1 so you need the term till a_5
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    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
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    (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
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    (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 a_{k+1}=-2a_k
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    (Original post by Unknown?)
    Yes thankyou I noticed. So the formula is a_{k+1}=-2a_k
    :yep:
 
 
 
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