Question

Write the explicit formula that represents the geometric sequence -2,8,-32,128.

Answer 1

Answer:

$a_{n}$ = - 2$(-4)^{n-1}$

Step-by-step explanation:

The n th term ( explicit formula ) for a geometric sequence is

$a_{n}$ = a$(r)^{n-1}$

where a is the first term and r the common ratio

Here a = - 2 and r = 8 ÷ - 2 = - 4, thus

$a_{n}$ = - 2$(-4)^{n-1}$