CPM Homework Help : CCG Problem 5-19

Examine each sequence below. State whether it is arithmetic, geometric, or neither. For the sequences that are arithmetic or geometric, find the formula for $t(n)$ or $a_n$ .

Hint:

Are the sequences decreasing at a constant rate?

$100$ , $10$ , $1$ , $0.1$ , $\dots$
Hint (a):
The equation for a geometric sequence is:
$a_n=a_1·b^{(n-1)}$ .
Answer (a):
$a_n=100\left(\frac{1}{10}\right)^{(n-1)}$

$0$ , $-50$ , $-100$ , $\dots$
Hint (b):
Refer to the Math Notes box in Lesson 4.1.3 for more help.