Question

What is the explicit formula for this geometric sequence? 8, 4 2, 1

Answer 1

Answer:

C

Step-by-step explanation:

The standard form for the explicit formula of a geometric sequence is given by:

$a_n=a\cdot(r)^{n-1}$

Where a is the initial term, r is the common ratio, and n is the nth term.

Our sequence is: 8, 4, 2, 1...

So, we can see that our initial term or a is 8.

Each subsequent term is half of the previous one. So, our common ratio is 1/2.

Let's substitute 8 for a and 1/2 for r to acquire:

$a_n=8\cdot(\frac{1}{2})^{n-1}$

So, our answer is C.

And we're done!