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Geometric Progression(GP): Formulae based
Example 4
Ex 8.2, 1
Example 5 Important
Ex 8.2, 5 (a)
Ex 8.2, 2
Example 6
Ex 8.2, 4 You are here
Ex 8.2, 3 Important
Ex 8.2, 17 Important
Example 7 Important
Ex 8.2, 7 Important
Ex 8.2, 10
Ex 8.2, 9 Important
Ex 8.2, 11 Important
Ex 8.2, 8
Ex 8.2, 19
Ex 8.2, 20
Example 8
Ex 8.2, 13
Ex 8.2, 15
Ex 8.2, 16 Important
Ex 8.2, 21
Ex 8.2, 14 Important
Misc 3
Misc 2
Example 9 Important
Ex 8.2, 12
Example 10 Important
Ex 8.2, 18 Important
Misc 11 (i) Important
Misc 5
Misc 1 Important
Geometric Progression(GP): Formulae based
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