How do the consecutive terms relate to each other?
Quadratic
Practice makes perfect
We want to identify which kind of model best describes the data: linear, quadratic or exponential. To do so we will calculate the difference between consecutive terms.
x
3
4
5
6
7
y
-1.5
0
2.5
6
10.5
Let's begin with calculating the first differences.
The first differences are not all equal. Therefore, the table of values does not represent a linear function. Let's find the second differences and compare them.
Since the second differences are all equal, the table of values represents a quadratic function.
