Quadratic Sequences

Question 1

What is a quadratic sequence?

Answer 1

Where a pattern’s second difference is constant (and non-zero).

Question 2

What is the general nth term of a quadratic sequence?

Answer 2

an² + bn + c

Question 3

How do you find ‘a’ in a quadratic sequence?

Answer 3

a = second difference / 2

Question 4

How do you find the nth term of a quadratic sequence

Answer 4

1. Find coefficient of n².
2. Draw a table with:
   - top: the sequence given to you
   - next: write the square numbers, and multiply the, by the coefficient of n²
   - next: subtract the two rows
   - you’ll now get a linear sequence
3. Find the nth term of the liner sequence, and add it to an².