In this example, you can see how to render and configure the trendlines. The trendline is a line drawn over the chart to display the overall direction of the results.
This chart supports the following types.
                        Tooltips are enabled in this example. To see a tooltip in action, hover over or tap on the chart.
                    
Injecting Module
                        Chart component features are segregated into individual feature-wise modules. To use Trend Line series, we need to inject
                        Trendlines module into services.
                    
More information on the TrendLines can be found in this documentation section.