Learn in your speed, with individual attention - Teachoo Maths 1-on-1 Class

Ex 8.2

Ex 8.2, 1

Ex 8.2, 2

Ex 8.2, 3 Important

Ex 8.2, 4 You are here

Ex 8.2, 5 (a)

Ex 8.2, 5 (b) Important

Ex 8.2, 5 (c)

Ex 8.2, 6

Ex 8.2, 7 Important

Ex 8.2, 8

Ex 8.2, 9 Important

Ex 8.2, 10

Ex 8.2, 11 Important

Ex 8.2, 12

Ex 8.2, 13

Ex 8.2, 14 Important

Ex 8.2, 15

Ex 8.2, 16 Important

Ex 8.2, 17 Important

Ex 8.2, 18 Important

Ex 8.2, 19

Ex 8.2, 20

Ex 8.2, 21

Ex 8.2, 22 Important

Ex 8.2, 23 Important

Ex 8.2, 24

Ex 8.2, 25

Ex 8.2, 26 Important

Ex 8.2, 27 Important

Ex 8.2, 28

Ex 8.2, 29 Important

Ex 8.2, 30 Important

Ex 8.2, 31

Ex 8.2, 32 Important

Chapter 8 Class 11 Sequences and Series

Serial order wise

Last updated at May 29, 2023 by Teachoo

Ex 8.2,4 The 4th term of a G.P. is square of its second term, and the first term is 3. Determine its 7th term. 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 = 3 Also, 4th term of G.P = (2nd term of G.P.)2 i.e. a4 = (a2)2 Putting values in (1) ar4 1 = (ar2 1)2 ar3 = (ar1)2 ar3 = (ar)2 ar3 = a2 r2 ^3/ ^2 = ^2/ ^(3 2) = ^(2 1) r1 = a1 r = a Putting a = -3 r = -3 Thus, r = -3 & a = -3 Now we need to find 7th term, we use the formula an = arn 1 Putting n = 7 , a = 3, r = 3 a7 = ( 3) ( 3)7 1 = ( 3) ( 3)6 = (-3) 729 = 2187 Hence, 7th term is 2187