The common difference in the arithmetic sequence 3, 12, 21, 30 is 9. According to the reference, this is indeed an arithmetic sequence, and its common difference is 9.
Understanding Arithmetic Sequences
An arithmetic sequence is a sequence of numbers such that the difference between any two consecutive terms is constant. This constant difference is called the common difference.
Calculating the Common Difference
To find the common difference in an arithmetic sequence, subtract any term from the term that follows it.
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Example: In the sequence 3, 12, 21, 30:
- 12 - 3 = 9
- 21 - 12 = 9
- 30 - 21 = 9
Since the difference between consecutive terms is consistently 9, the common difference is 9.
Table Summary
| Term | Value |
|---|---|
| First Term (a1) | 3 |
| Second Term (a2) | 12 |
| Third Term (a3) | 21 |
| Fourth Term (a4) | 30 |
| Common Difference (d) | 9 |
