First of all, select the whole dataset (the range B4:C12).

Follow these steps to plot a curve from the dataset. To calculate the slope of the polynomial trendline, we need to plot the curve first in an Excel spreadsheet.

As Excel can only provide polynomial trendlines of degrees up to 6, we can use formulas to make a custom dataset that can calculate the slope at different points.įor demonstration, we are using the following dataset.įollow these detailed steps to see how we can measure the slope of the curve plotted from the dataset. But fear not, we can still work around that with excel tools. The general idea to find the slope of these types of polynomial trendlines is to differentiate y with respect to x, and insert the abscissa of the point in the differentiated equation. Step-by-Step Process to Find Slope of Polynomial Trendline in ExcelĪs a polynomial trendline is a curve, the slope will be different at different points of the curve- which can not be directly derived in Excel till now. Among the polynomial curves, a quadratic one has 1 bend, a cubic one has typically 2 bends, and so on. These bends are generally called hills or valleys depending on their shapes. The degree of the polynomial curve is determined by the number of bends in the curve, as it is directly proportional to the degree of the equation it represents. This movement indicates the oscillating values on the y axis.

In a polynomial trendline, the trendline curve moves upwards and downwards multiple times. This trendline can be linear or move in various upward and downward directions. It generally measures the change of a particular parameter, like y, with respect to another parameter(like x values). A trendline, as the name suggests, indicates the trend of change of variables in a graph.

How to add trendline equation in excel