Is the sequence an arithmetic sequence?
3, 6, 9, 12, 15, …
How do you know whether a sequence is arithmetic?
The differences between consecutive terms are the same in an arithmetic sequence.
Find the differences between consecutive terms.
Each difference is 3. The sequence has a common difference. The sequence is an arithmetic sequence.
1, 4, 9, 16, 25, …
Find the difference between consecutive terms.
There is no common difference. The sequence is not an arithmetic sequence.
What is the 100th term of the arithmetic sequence that begins 6, 11, …?
The first term a is 6. The common difference d is
The 100th term is 501.
What are the second and third terms of the arithmetic sequence
What do you need to find the second term given the first term?
You need to know the common difference of the arithmetic sequence.
The first term a is 100. The fourth term
The common difference is
The second and third terms are 94 and 88.