This week in pre-calc 11 we learned about geometric sequences and series. An important part in these is the common ratio, it shows the difference between the terms by the term being multiplied by the constant.

The formula to find the CR is: $r= \frac {t_n}{t_n-1}$

Example: 4, 8, 16, 32

If you’re looking for the common ratio we need to divide 8 by 4.

$r= \frac {8}{4} = 2$

You could also do $r= \frac {32}{16} = 2$ As long as you use a term that precedes $t_n$ as the denominator you will get the right answer for the common ratio.