select the five terms

Question

Select the first five terms in the geometric sequence a n =(2)^n-1 , starting with ^n=1


A. (2,4,8,16,64)

B. (1,2,4,8,16)

C. (1,2,4,6,8)

 

D. (2,4,6,8,10)

Answer 1

n₁ = 2^1-1 = 2⁰ = 1

n₂ = 2^2-1 = 2¹ = 2

n₃ = 2^3-1 = 2² = 4

n₄ = 2^4-1 = 2³ = 8

n₅ = 2^5-2 = 2⁴ = 16

 

B.

Answer 2

The answer is b see the comment above for the explanation