Question

What is the explicit formula for this sequence?

2,6, 18, 54, 162..
h
A. an=2(3)"
B. an = 2 + 3(n-1)
c. A = 3(2)(n-1)
D. an
2(3)(n-1)

Answer 1

D. aₙ= 2*3ⁿ⁻¹

Explanation:

It is GP with common ratio of 3 as 6/2=18/6=54/18=162/54= 3 and the first term of 2

then aₙ= 2*3ⁿ⁻¹ is the formula

Option D is correct one

Answer 2

D.

Explanation:

r = 3

a1 = 2

Our explicit formula is an = a1 (r)^(n-1)

Simply plug in the terms

an = 2(3)^(n-1)