If the sum of first n terms of an A.P. is 3n² + 2n, find its r^th term.

Question

KnowledgeBoat · Accepted Answer

By formula, S_n = Given, S_n = 3n² + 2n Equating values we get : As, S_n = 3n² + 2n S₁ = 3(1)² + 2(1) = 3 + 2 = 5. ∴ a = 5. Substituting value in (1), we get : ⇒ 6n + 4 = 5 + a_n ⇒ a_n = 6n - 1 ⇒ a_r = 6r - 1 Hence, r_th term = 6r - 1.

Mathematics

If the sum of first n terms of an A.P. is 3n² + 2n, find its r^th term.

AP GP

Related Questions

If p^th term of and A.P. is q and its q^th term is p, show that its r^th term is (p + q - r).

If n^th term of an A.P. is (2n - 1), find its 7^th term.

For an A.P. the sum of its terms is 60, common difference is 2 and last term is 18. Find the number of terms in the A.P.

Find the geometric progression whose 5^th term is 48 and 8^th term is 384.

Mathematics

If the sum of first n terms of an A.P. is 3n2 + 2n, find its rth term.

AP GP

Related Questions

If pth term of and A.P. is q and its qth term is p, show that its rth term is (p + q - r).

If nth term of an A.P. is (2n - 1), find its 7th term.

For an A.P. the sum of its terms is 60, common difference is 2 and last term is 18. Find the number of terms in the A.P.

Find the geometric progression whose 5th term is 48 and 8th term is 384.

If the sum of first n terms of an A.P. is 3n² + 2n, find its r^th term.

If p^th term of and A.P. is q and its q^th term is p, show that its r^th term is (p + q - r).

If n^th term of an A.P. is (2n - 1), find its 7^th term.

Find the geometric progression whose 5^th term is 48 and 8^th term is 384.