Math 1 · Unit 9 · Lesson 2 · part 1 of 5
The Words We Use
The vocabulary for this lesson, in one place.
Words we use
| Word | Plain English | What you do |
|---|---|---|
| Arithmetic sequence | A list that adds the same amount each time. | Its dots sit on a line. |
| Common difference, d | The amount added each time. It is the slope. | Subtract any term minus the one before. It can be negative. |
| Recursive rule | How to get the next term from the one before. The stairs. | a1 = start, an = an − 1 + d. |
| Explicit rule | How to find any term from its term number. The elevator. | an = a1 + d(n − 1). |
| Zeroth term | The term one step before the first. It is the y-intercept. | a1 − d. It sits at n = 0. |
| n − 1 | The number of steps from the first term to the nth. | One less than the term number. |