Question

17) Find the 8th term of the G.P 9,3,1,​

Answer 1

Answer:

a=9 , d=6 n=8

a+(n-1)d = an

9+(8-1)6 = an

9+7×6 = an

9+42 = an

51 = an

Answer 2

Given,

T1 = 9

T2 = 3

T3 = 1

and terms are in G.P.

To Find,

T8 = ?

Solution,

Common ration of G.P. = Tn/ Tn-1.= 3/9 = 1/3

Formula for nth term in G.P. = $T_n = ar^{n-1}$

$T_n = ar^{n-1}$

Putting values in this formula we get,

$T_{8} = 9* (1/3)^{8-1}$

$T_{8} = 9*(1/3)^{7}$

$T_{8} = (3)^2(1/3)^{7}.$

$T_{8} =(1/3)^5$

$T_{8} = \frac{1}{243}$

Hence, the 8th term of G.P. is 1/243.