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    I am a GCSE student doing the intermediate paper. I have a past paper the teacher has given me to do and I am really stuck on one question. The teacher considers me able and so do I because i get 80%-90% all the time.

    Anyway here is the question:
    Complete the pattern
    Pattern Number- 1 2 3 4 5
    No. Of Crosses- 1 5 13 25 41

    What is the Nth term i have tried all sorts. The differences are 4,8,12,16 so i know for definate it is n squared but what else.

    Please help
    Richard
    P.S thanx for any help in advanced
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    The pattern is n^2 + (n-1)^2

    For example, if n=3, you get

    (3^2) + (2^2) = 9 + 4 = 13

    Hope this helps,
    Michael
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    (Original post by RuedaNT)
    I am a GCSE student doing the intermediate paper. I have a past paper the teacher has given me to do and I am really stuck on one question. The teacher considers me able and so do I because i get 80%-90% all the time.

    Anyway here is the question:
    Complete the pattern
    Pattern Number- 1 2 3 4 5
    No. Of Crosses- 1 5 13 25 41

    What is the Nth term i have tried all sorts. The differences are 4,8,12,16 so i know for definate it is n squared but what else.

    Please help
    Richard
    P.S thanx for any help in advanced
    n^2 + (n-1)^2
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    (Original post by RuedaNT)
    I am a GCSE student doing the intermediate paper. I have a past paper the teacher has given me to do and I am really stuck on one question. The teacher considers me able and so do I because i get 80%-90% all the time.

    Anyway here is the question:
    Complete the pattern
    Pattern Number- 1 2 3 4 5
    No. Of Crosses- 1 5 13 25 41

    What is the Nth term i have tried all sorts. The differences are 4,8,12,16 so i know for definate it is n squared but what else.

    Please help
    Richard
    P.S thanx for any help in advanced
    n^2+(n-1)^2=2n^2-2n+1
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    How do you know that, trial and error?
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    (Original post by mik1a)
    How do you know that, trial and error?
    well as second difference is same, u know it involves n^2, now see difference between the n^2 value and final value...i noticed that difference between these was a perfect square, which happened to be that of the number below n


    wouldnt mind a bit of rep...here and there everybody :-)
 
 
 
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