Question

What are the explicit equation and domain for a geometric sequence with a first term of 4 and a second term of −8?

Answer 1

Answer:

Option B is right

Step-by-step explanation:

Given:

There is a geometric sequence with first term =4

and second term =-8

We know that a geometric sequence is a sequence of numbers, in which each successive number is got by multiplying the previous number by a fixed value called common ratio.

First term is called a.

and common ratio is denoted by r.

The terms would be

$a,ar,ar^{2} ,...$

Here we have a=4 and ar =-8

So r =common ratio =-2

nth term we mean n can take values as 1,2.....

So general term

$a_{n}=ar^{n-1}\\ =4(-2)^{n-1},n\geq1$

is right answer

Hence option b.