How to find the gradient of a section of a graph on excel?

I have created a graph on excel which starts as a line gradient 0 then increases in gradient to another constant gradient line (not of 0). Is there anyway i can find the gradient of this 2nd constant gradient section of the line?How to find the gradient of a section of a graph on excel?
It may be just a bit easier if the chart type is Scatter than if it is Line so change the chart type if necessary (Right click in the chart and select Change Chart Type.)





Arrange the data table and chart so that you can see both at the same time. If you would have any trouble reentering the data in the left column of the data table, copy and paste it somewhere that you can retrieve it from. You can leave the second column alone.





Watching the chart to guide and confirm your actions, delete the contents of all cells in the left column that are NOT part of the second gradient section.





With just the second gradient section of the line in the chart, right click on a data point and select Add Trendline. Select the Linear type and select Display Equation on Chart (in the Options tab for Excel 2003). Select Close (or OK) and return to the chart.





The equation will be in the form of y = mx + b where m is the gradient. (If there is no value in front of the x then the gradient is 1. If there is no x in the equation then the gradient is 0.)








Another approach would be to move all of the second column entries for the second section one column to the right and right click on the chart to select Select Data in include the new column in the chart. That way both sections are visible on the chart as separate lines. And you could continue this for as many sections as you want. The common point(s) between two sections would appear in both columns but only one marker would show. Using a chart type of Scatter with lines (Smooth or straight) should improve the chart appearance.