Question

The formula for any geometric sequence is an = a1 · rn - 1 , where an represents the value of the n th term, a1 represents the value of the first term, r represents the common ratio, and n represents the term number. What is the formula for the geometric sequence 4, 8, 16, 32, ...? an = 4 · ( ) n - 1 an = 2 · 4 n - 1 an = 32 · 2 n - 1 an = 4 · 2 n - 1

Answer 1

an = 4 · 2^(n - 1)

Explanation:

Answer 2

an = 4 · 2^(n - 1)

Explanation:

Given:

an = a1 · r^(n - 1)

Where,

an = value of the n th term

a1 = value of the first term

r = common ratio

n = the term number.

What is the formula for the geometric sequence 4, 8, 16, 32, ...?

a1 = 4

r = 8/4

= 2

n = n(not given)

Substitute the values of a1 and r into the formula

a1 = 4

r = 2

an = a1 · r^(n - 1)

an = 4 * 2^(n - 1)

The correct answer is:

an = 4 · 2^(n - 1)