CPM Homework Help : CCG Problem 4-29

Examine each sequence below. State whether it is arithmetic, geometric, or neither. For the sequences that are arithmetic or geometric, find the equation for $t(n)$ or $a_n$ . Refer to the Math Notes box in this lesson if you need additional help.

Hint:

Is the sequence increasing at a constant rate through addition or mulitplication?

$1$ , $4$ , $7$ , $10$ , $13$ , …
Hint (a):
The common difference of this sequence is $3$ .
More Help (a):
Follow the steps in the Math Notes box for writing the equation of an arithmetic sequence.
Answer (a):
Arithmetic:
$a_n=1+3(n-1)=3n-2$

$0$ , $5$ , $12$ , $21$ , $32$ , …
Answer (b):
Neither

$2$ , $4$ , $8$ , $16$ , $32$ , …
Hint (c):
See the Math Notes box in this lesson.
Answer (c):
Geometric:
$a_n=2·2^{n-1}=2^n$

$5$ , $12$ , $19$ , $26$ , …
Hint (d):
Follow the instructions from part (a).