Q5 of 102 Page 429

The 9^th term of an AP is 0. Prove that its 29^th term is double the 19^th term.

Given :9^th term is 0

To prove: 29^th term is double the 19^th term

a + 8d = 0

a = - 8d

29^th term is

a + 28d

⟹ 20d

19^th term is

a + 18d

⟹ 10d

Hence proved 29^th term is double the 19^th term

In an AP it is given that S_n = qn² and S_m = qm². Prove that S_q = q³.

Find three arithmetic means between 6 and - 6.

How many terms are there in the AP 13, 16, 19, …., 43?

Find the 8^th term from the end of the AP 7, 9, 11, …., 201.

The 9th term of an AP is 0. Prove that its 29th term is double the 19th term.