Question

Find the 9th term of the G.P. 2, 1, `1/2`, ......

Answer 1

a = 2

r = `1/2`

`a_n = ar^(n - 1)`

`a_9 = ar^(9 - 1)`

a₉ = ar⁸

= `2 xx (1/2)^8`

= `2 xx 1/2^8`

=`1/2^7`

` a_9 = 1/128`