Subscribe to our Youtube Channel - https://you.tube/teachoo

Last updated at May 29, 2018 by Teachoo

Transcript

Ex 9.3, 17 If the 4th, 10th and 16th terms of a G.P. are x, y and z, respectively. Prove that x, y, z are in G.P. 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, 4th term is x i.e. a4 = x Putting n = 4 in an formula x = ar4 1 x = ar3 Also, 10th term is y i.e. a10 = y Putting n = 10 in an formula y = ar10 1 y = ar9 Also, 16th term is z i.e. a16 = z Putting n = 16 in an formula z = ar16 1 z = ar15 We need to show x, y, z are in GP i.e. we need to show / = / Calculating / / Putting y = ar9 & x = ar3 = 9/ 3 = r9 3 = r6 Now calculating / / putting z = ar15 & y = ar9 = 15/ 9 = r15 9 = r6 Thus, / = r6 , & / = r6 Hence / = / x, y, z are in G.P Hence proved

Ex 9.3

Ex 9.3, 1

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 You are here

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 9 years. He provides courses for Maths and Science at Teachoo.