I have data from Google Trends and Center for Disease control that I want to compare. I used regression analysis from Excel to find a curve of best fit. The original data is in this form:
It was impossible to entirely model this using excel so I broke it down into two parts and found a curve of best fit for those two.
The goal is to compare this data with another graph I made with Google Trends (same process, break it down and regression) and assess to what extent is it accurate to use search engine queries to predict flu seasons. If I want to find the graph of the derivative of the original data to look at rates of change, can I take the derivatives of the two smaller functions and compile them together?