# Quadratic Sequences (finding Nth term) STEP-BY-STEP

**Shows you how to find the nth term for a quadratic sequence (one where the differences are not equal) using an example! **

Teacher recommended

- Created by: Katy
- Created on: 24-05-12 19:07

First 82 words of the document:

QUADRATIC SEQUENCES

Example (apply to all quadratic sequences):

4 7 12 19 28

FIND THE FIRST DIFFERENCE:

4 7 12 19 28

3 5 7 9

FIND THE SECOND DIFFERENCE:

3 5 7 9

2

N

2 2 2 2nd difference. If it were a 2nd

difference of 4 it would be N4.

Write in a table. N 2 is the normal nth terms 2 . Then find

the difference between sequence number and N 2 :

Term 4 7 12 19 28

Nth term 1 2 3 4 5

N(2) 1 4 9 16 25

Difference 3 3 3 3 3

(term-N2)

12-9 = 3

2

Nth term = N + 3

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