9.2/9.3 Quiz Review
FORMULAS:
Name: ________________________ Per: _____
Arithmetic Sequence
Geometric Sequence
an a1 (n 1)d
an a1 r n 1
Example:
SYMBOLS:
Example:
an =
a1 =
n=
d=
r=
For each of the following sequences, determine if it is arithmetic or geometric. If it is arithmetic, state the common
difference. If it is geometric, state the common ratio.
1.
3, 12, 21, …
arithmetic: d = ______
geometric: r = _______
neither
2.
3, -12, 48, …
arithmetic: d = ______
geometric: r = _______
neither
3.
3, 9, 18, …
arithmetic: d = ______
geometric: r = _______
neither
4.
1 1
, ,1,...
4 2
arithmetic: d = ______
geometric: r = _______
neither
---------------------------------------------------------------------------------------------------------------------------------------------------------5. What is the 22nd term of the arithmetic
sequence with a1 3 and d 4 ?
6. What is the 100th term of the arithmetic sequence
that begins -5, -8, -11, …. ?
Find the missing terms for the following arithmetic sequences.
7.
5, ____, _____, ____, 21
8.
148, _____, 128
__________________________________________________________________________________________________
9. You decide to save money for college. Your grandmother gives you a brand new $100 bill. You decide to add $10
each month. At the end of the second month, you have $110. At the end of the third month, you have $120. How
much will you have in one year? (at the end of the 12th month)
---------------------------------------------------------------------------------------------------------------------------------------------------------------10.
What is the 13th term of the geometric sequence
11.
What is the 10th term of the geometric
where a1 128 and r
1
?
2
that begins 28, 42, 63, …
-------------------------------------------------------------------------------------------------------------------------------------------------------------Find the missing terms for the following geometric sequences.
12.
-1.5, _____, ______, -187.5
13.
32, ____, 8
0
