Question

Which exponential function describes the given sequence?

3, 9, 27, 81...

A) y = (- 1 3 )x
B) y = 1 3 x
C) y = (-3)x
D) y = 3x

Answer 1

D

Explanation:

The common ratio is 3. The first term is 3 or 31; the second term is 9 or 32; the third term is 27 or 33; the fourth term is 81 or 34. The correct answer is y = 3x.

Answer 2

Since the number are multiple exponents of 3 (3^1, 3^2, 3^3, 3^4...), then we could write it as:
D) y = 3^x