if the sum of first n terms of an ap is 4n-n^2 what is the first term? what is the sum of first 2 terms? what is the second term?

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if the sum of first n terms of an ap is 4n-n^2 what is the first term? what is the sum of first 2 terms? what is the second term?

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Arianna 3 days 2021-11-24T22:59:57+00:00 1 Answer 0 views 0

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    2021-11-24T23:01:03+00:00

    Step-by-step explanation:

    Sn = 4n -n^2

    Just Think The Given Equation Of The Sum Of ” n ” Terms Is correct for all the terms in the AP , So If you put n=1 You get Sum of 1 terms which is actually the value of first term a1 .

    It goes like this ,

    Sn = 4n – n^2

    = 4(1) – (1)^2

    = 4 – 1 = 3

    so The First Term Is 3.

    Sum Of 2 Terms Is …

    S2 = 4(2) – (2)^2 = 4

    Sum of first 2 Terms means a1 + a2 ,

    Now you know a1 and S2 , so S2 – a1 = a2 = 4-3= 1

    Now the common difference ,

    a2- a1 = d = 1-3 = -2.

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