Question

Find 10th term of a geometric sequence whose first two terms are 2 and -8. Please answer!!

Answer 1

The 10th term is -524,288

Explanation:

The general format of a geometric sequence is:

`a_(n) = r*a_(n-1)`

In which r is the common ratio and
`a_(n+1)` is the previous term.

We can also use the following equation:

`a_(n) = a_(1)*r^(n-1)`

In which
`a_(1)` is the first term.

The common ratio of a geometric sequence is the division of the term
`a_(n+1)` by the term
`a_(n)`

In this question:

`a_(1) = 2, a_(2) = -8, r = (-8)/(2) = -4`

10th term:

`a_(10) = 2*(-4)^(10-1) = -524288`

The 10th term is -524,288