Question

The sum of first n terms of an AP is (4n² + 2n). The nth term of this AP is ______.

विकल्प

• (6n – 2)

• (7n – 3)

• (8n – 2)

• (8n + 2)

Answer 1

The sum of first n terms of an AP is (4n² + 2n). The nth term of this AP is (8n – 2).

Explanation:

T_n = (S_n – S_{n – 1})

= (4n² + 2n) – {4(n – 1)² + 2(n – 1)}

= (4n² + 2n) – (4n² – 6n + 2)

= (8n – 2)