Quadratic Function
FIRST AND SECOND DIFFERENCES
To get started off... First or second differences are used to determine whether the equation we talk about is linear, quadratic, or neither. You would set up your chart as observed...
As you can also see, your numbers from your y-axis (Output) have been lined up as well in each column.
As you can see, the x-axis (Input) has been set up and adding up every column by one.
When finding the first difference, you always use a set of y-axis numbers. You would subtract the number from its previous number in the y axis column. As you can see, the numbers do not equal to one number which means it is not (linear).
If the first difference is not same, then you need to find the second difference by following the same process again but you must begin at the first difference column (starting at the second number). If the second difference is same then the equation is considered to be a (non-linear) as it shows on the chart above. If second difference is not same then, the equation is considered to be (neither).