how to get an equation from trendline excel

If you omit new_x's, it is assumed to be the same as known_x's,.

new_x's (optional) are the new x-values for which the TREND () function should calculate corresponding y-values:.

a 2: = INDEX (LINEST (known_y's, known_x's ^ that is the same size as known_y's,.

Quadratic (2 nd order or 2 nd degree) polynomial trendline Now the variable y does not depend on one variable x in n different degrees but on n independent variables X i.Įxcel offers the following functions to calculate the trend parameters:

After changing the variables to X i = x i, the calculations are completely similar to the linear case y = a n*X n +. + a 3*x 3 + a 2*x 2 + a 1*x + b is transformed to a linear function using a change of variables. Note: Excel uses a linear model: the polynomial function y = a n*x n + .

Excel works with polynomial orders from 2 nd to 6 th. n is the degree of the polynomial (in Excel, the order of a polynomial)., a 3, a 2, a 1 and b are calculated parameters of the function (also named function coefficients or constants) that describe the relationship between x and y, The polynomial trendline is a curved line with the function: Polynomial trendline equation and formulas a dependent or response variable y (named as known_y's).an independent, predictor, or explanatory variable x (named as known_x's),.The degree of the polynomial is specified in the Order field - see more about the polynomial trendline in Excel.Įxcel uses the least squares method to fit a polyline for the data points.įor a trend line, two sets of variables are required:

How to get an equation from trendline excel