What makes a table quadratic?
The definition of a quadratic relationship is that the 2nd difference is constant in the dependent variable (DV/ y-value).
So, unlike a linear relationship where the 1st difference is constant, the second difference is constant in a quadratic relationship.
So, unlike a linear relationship where the 1st difference is constant, the second difference is constant in a quadratic relationship.
Quadratic:
Not quadratic: