MDHS Precalculus
9.2
Recommended reading: Section 9.2 in text.
Arithmetic Sequences and Partial Sums
Objectives:
1.
Recognize, write, and find the
terms of arithmetic sequences.
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n
2.
Find
partial sums of arithmetic sequences.
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n
Arithmetic Sequences
A sequence whose consecutive terms have a common difference is called an
arithmetic
sequence.
Example 1
Arithmetic Sequences
The sequence whose
term is
is arithmetic. For this sequence, the common difference
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n
n
4
+ 3
between consecutive terms is 4.
Find the first 5 terms.

Example 2
Finding the
Term
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n
Find a formula for the
term of the arithmetic sequence whose common difference is 3 and
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n
whose first term is 2.
Example 3
Using a Recursion Formula
Find the ninth term of the arithmetic sequence that begins with 2 and 9.
The Sum of a Finite Arithmetic Sequence
There is a formula for the
sum
of a finite arithmetic sequence.