Maths C1 Series and Sequences Watch

Arman47
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Hi,
Im stuck on this question: "Prove that the (2n+1)th term of the sequence Un=n^2 -1 is a multiple of 4."

I've substituted the "(2n+1)" as "n" into the formula and got "U 2n+1=4n^2+4n+1-1" so i ended up with "U2n+1=4n^2+4n"... I don't know what to do from here on...

Help would be great, thanks
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She-Ra
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(Original post by Arman47)
Hi,
Im stuck on this question: "Prove that the (2n+1)th term of the sequence Un=n^2 -1 is a multiple of 4."

I've substituted the "(2n+1)" as "n" into the formula and got "U 2n+1=4n^2+4n+1-1" so i ended up with "U2n+1=4n^2+4n"... I don't know what to do from here on...

Help would be great, thanks
Moved to the maths forum for you
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TenOfThem
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(Original post by Arman47)
Hi,
Im stuck on this question: "Prove that the (2n+1)th term of the sequence Un=n^2 -1 is a multiple of 4."

I've substituted the "(2n+1)" as "n" into the formula and got "U 2n+1=4n^2+4n+1-1" so i ended up with "U2n+1=4n^2+4n"... I don't know what to do from here on...

Help would be great, thanks
Are you saying that you have 4n^2 + 4n and you cannot show that it is a multiple of 4?
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Arman47
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(Original post by TenOfThem)
Are you saying that you have 4n^2 + 4n and you cannot show that it is a multiple of 4?
In the answer section it says "Un=4n^2+4n" so i got confused because i ended up with "U2n+1=4n^2+4n"...
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Arman47
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(Original post by She-Ra)
Moved to the maths forum for you
Thanks ^___^
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TenOfThem
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(Original post by Arman47)
In the answer section it says "Un=4n^2+4n" so i got confused because i ended up with "U2n+1=4n^2+4n"...
U_{2n+1} = 4n^2 + 4n = 4(n^2 + n)

Is the answer that you are looking for
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Arman47
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Thanks
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