Question

Write an equation for the nth term of this sequence: 1/8, 1/4, 1/2, 1..

Answer 1

Answer:

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

Step-by-step explanation:

This is a geometric sequence.  You start with the first term, 1/8, then multiply it by 2 to get 1/4, then double that to get 1/2, etc.

The number you multiply by is called the common ratio.  In this case, the common ratio is 2.

A formula for the general (nth) term is:  $a_n=a_1 r^{n-1}$.

$a_1=1/8\\r=2$

So the nth term is $a_n=\frac{1}{8} (2^{n-1})$