CPM Homework Help : INT1 Problem 7-48

For parts (a) and (b), write a recursive equation using $a_{n}$ notation for each sequence. For parts (c) and (d), write an explicit equation using $t(n)$ notation for each sequence. (For a reminder about sequence notation, see the Math Notes box in Lesson 5.3.2.)

Hint (all):

Read Math Notes box in Lesson 5.3.3 on equations for sequences.

$108, 120, 132, …$
Answer (a):
$a_{1} = 108$
$a_{n+1} = a_{n}+12$

$\frac { 2 } { 5 },\frac{4}{5},\frac{8}{5}, ...$
Answer (b):
$a_1=\frac{2}{5}$
$a_{(n+ 1)} = 2a_{n}$

$3741, 3702, 3663, …$
Hint (c):
Is the sequence arithmetic or geometric?
Remember to write an explicit equation.

$117, 23.4, 4.68, …$
Hint (d):
Is the sequence arithmetic or geometric?
Remember to write an explicit equation.