Question

Which exponential functions describes the given sequence?

Sequence: 3 , 9 , 27 , 81

y = (-1/3) ^ x
y = (1/3) ^ x
y = (-3) ^ x
y = 3 ^ x

Answer 1

I only know it's times 3 to get each next term. But how do I know which of the functions is it?

Answer 2

Hint: do 3, 9 , 27, 81, ... seem to have a common base? If so, what is that base?

Answer 3

What is "common base" ?

Answer 4

3^1 , 3^2 , 3^3 , 4^3

Answer 5

One way would be to graph each of the answer choices (but that'd take some time!).

Another way would be to think in terms of exponential functions.
What are the values of 3^1, 3^2, 3^3, 3^4?

Here 3 is the "common base".

In an exponential function, you have a "base" and you are raising that base to various powers.

Answer 6

So would it be D and the x would represent number of the term. Like if x is 1 it's the first term, if x is 2 it's the second term

Answer 7

Right?

Answer 8

Yes. Thanks for explaining your reasoning.

Answer 9

thank YOU !