• Math

  Sequence

  Posted by Anagha on June 24, 2023 at 8:46 pm

  In an A.P., if Sn = 3n2 + 2n, then the value of d ?

  Nitesh replied 4 months, 1 week ago 2 Members · 1 Reply
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  Nitesh

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  January 5, 2024 at 2:32 pm

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  To find the common difference (d) in an arithmetic progression (A.P.) when the sum of the first ‘n’ terms (Sn) is given, we can use the following formula:

  Sn = (n/2) * [2a + (n-1)d]

  where ‘a’ is the first term and ‘d’ is the common difference.

  In the given problem, Sn = 3n^2 + 2n.

  Substituting this into the formula, we have:

  3n^2 + 2n = (n/2) * [2a + (n-1)d]

  Simplifying further:

  3n^2 + 2n = (n/2) * [2a + nd – d]

  Now, let’s equate the coefficients of n^2 and n on both sides:

  3 = d/2

  Multiplying both sides by 2, we get:

  6 = d

  Therefore, the value of ‘d’ in the arithmetic progression is 6.

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