Question

If sum up to n terms of any sequence is given by Sn2(3n-1). Find the 3rd term.

Answer 1

Answer:

$꧁༒༈༺࿙αиѕωєя࿚༻༈༒꧂$

Step-by-step explanation:

Let an be the nth term of the A.P.

Let an be the nth term of the A.P. Then, an=Sn−Sn−1

Let an be the nth term of the A.P. Then, an=Sn−Sn−1⟹an=(5n2+3n)−{5(n−1)2+3(n−1)}

Let an be the nth term of the A.P. Then, an=Sn−Sn−1⟹an=(5n2+3n)−{5(n−1)2+3(n−1)} [Replacingnby(n−1)inSntogetSn−1=5(n−1)2+3(n−1)]

Let an be the nth term of the A.P. Then, an=Sn−Sn−1⟹an=(5n2+3n)−{5(n−1)2+3(n−1)} [Replacingnby(n−1)inSntogetSn−1=5(n−1)2+3(n−1)]⟹an=(5n2+3n)−(5n2−7n+2)

Let an be the nth term of the A.P. Then, an=Sn−Sn−1⟹an=(5n2+3n)−{5(n−1)2+3(n−1)} [Replacingnby(n−1)inSntogetSn−1=5(n−1)2+3(n−1)]⟹an=(5n2+3n)−(5n2−7n+2)⟹an=10n−2