Polynomial Trending

You're probably familiar with linear trending. Those situations represent trends that move in (relatively) straight lines. The increase in U.S. population over the past 50 years. The increase in ear hair as men grow older. That sort of thing.

The graph of a polynomial trend looks much different. Instead of a line going either straight up or straight down, a polynomial trend will appear as a curve. It will have high parts and low parts...peaks and troughs.