Sets or returns the type of regression used to construct this trendline.

 public Regression RegressionType{ get; set; }

Public Property RegressionType() As Regression

This object will return a Trendline.Regression value specifying what sort of equation is used to calculate the trendline. Note that linear trendlines have a RegressionType of Polynomial, with a Trendline.RegressionValue of 1.