Math 1 · Unit 9 · Lesson 4 · 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 |
|---|---|---|
| Recursive rule | How to get the next term from the one before. The stairs. In plain words: Next = Now + 12. | It needs the starting term. |
| Explicit rule | How to find any term straight from its term number. The elevator. | Put in n and calculate once. |
| Initial term | a1, the starting point a recursive rule needs. | Without it you cannot start climbing. |
| an + 1, said a sub n plus 1 | The next term, the one after an. Same as f(n + 1). | In Now-Next words: Next. |
| an − 1, said a sub n minus 1 | The previous term, the one before an. Same as f(n − 1). | Each term is built from it. |
| Translate | Change a rule from one form to the other without changing the list. | Find the start; find d or r; write the other form. |