Question

Select the formula for the
xth term of the sequence.

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Answer 1

Option (3)

Explanation:

Given sequence is,

8, -8, 8,...........

Ratio of the 2nd and 1st term =
`(-8)/(8)`

= -1

Ratio of 3rd and 2nd term =
`(8)/(-8)`

= -1

Therefore, there is a common ratio 'r' = (-1)

And the sequence is a geometric sequence.

Explicit formula for the nth term of a geometric sequence is given by,

`T_n=a(r)^(n-1)`

Here, 'a' = First term of the sequence

r = Common ratio

n = nth term

For the given sequence xth term of the sequence will be,

`T_x=8(-1)^(x-1)`

Option (3) will be the answer.