Last updated at May 29, 2018 by Teachoo

Transcript

Ex 9.3, 1 Find the 20th and nth terms of the G.P. 5/2, 5/4, 5/8,…. G.P. is 5/2, 5/4, 5/8,…. We know that an = arn – 1 where an = nth term of GP n is the number of terms a is the first term r is the common ratio Here, First term a = 5/2 Common ratio r = (5/4)/(5/2) = 5/4 × 2/5 = 1/2 We need to find nth term, nth term of GP = an = arn-1 Putting a = 5/2 , d = 1/2 = 5/2 (1/2)^(𝑛−1) = 5/2 (1/2^(𝑛−1) ) = (5/(〖2 (2〗^(𝑛−1)))) = 5/(2)"n − 1 + 1" = 5/2^𝑛 Hence, the nth term of GP is 5/2^𝑛 For 20th term of GP Putting n = 20 in an a20 = 5/2^20 Thus, 20th term of GP is 5/2^20

Ex 9.3, 1
You are here

Ex 9.3, 2

Ex 9.3, 3 Important

Ex 9.3, 4

Ex 9.3, 5

Ex 9.3, 6

Ex 9.3, 7

Ex 9.3, 8

Ex 9.3, 9

Ex 9.3, 10

Ex 9.3, 11 Important

Ex 9.3, 12

Ex 9.3, 13

Ex 9.3, 14

Ex 9.3, 15

Ex 9.3, 16

Ex 9.3, 17 Important

Ex 9.3, 18 Important

Ex 9.3, 19

Ex 9.3, 20

Ex 9.3, 21

Ex 9.3, 22 Important

Ex 9.3, 23

Ex 9.3, 24

Ex 9.3, 25

Ex 9.3, 26

Ex 9.3, 27 Important

Ex 9.3, 28 Important

Ex 9.3, 29 Important

Ex 9.3, 30

Ex 9.3, 31

Ex 9.3, 32

Chapter 9 Class 11 Sequences and Series

Serial order wise

About the Author

Davneet Singh

Davneet Singh is a graduate from Indian Institute of Technology, Kanpur. He has been teaching from the past 8 years. He provides courses for Maths and Science at Teachoo. You can check his NCERT Solutions from Class 6 to 12.