This Tangent app is for plotting the tangent line along a curve. When using this app, Origin adds a vertical line to the graph, allowing you to move the vertical line to select a point from curve.
A Tangent Preferences dialog is available from the fly out menu. You can save tool settings to a theme file for later use.
When the curve is not smooth, the tangent line may not be well-fitted to the curve. In such cases, we can use smoothing to affect the calculated derivatives. This tool supply the Smooth method, On the Derivative tab of the Tangent Preferences dialog box, choose B-Spline or Savitzky-Golay from the Smooth list.
You can update output for the tangent line using the fly-out menu of the app. Also, you can customize the output data and position on the Output tab of Tangent Preferences dialog.