To find the equation of a polynomial graph on Excel, you can use the LINEST function. This function will calculate the coefficients of a polynomial equation that best fits a set of data points. To use the LINEST function, enter the data points into two columns of a spreadsheet. Then, enter the LINEST function into a third column, with the two columns of data points as the arguments. The LINEST function will return the coefficients of the polynomial equation that best fits the data points.
