Insert tangent/normal

You can use the dialog below to insert or edit a tangent or normal to a function. To insert a new tangent or normal, you use FunctionInsert tangent/normal.... To change an existing tangent or normal, you first select it in the function list and use FunctionEdit....

A tangent is a straight line that touches the graph of the function at a given point without crossing it. The tangent may however cross the graph elsewhere. A normal is a straight line perpendicular to the graph of the function at a given point. If the item is a standard function the point is identified by the x-coordinate, while the point is identified from the independent t-parameter for parametric and polar functions.

Argument range

You can choose an interval for the tangent/normal. From and To indicates the start and end of the interval. You can leave one or both of them blank to draw the graph from minus infinity to plus infinity.


Here you can choose to show markers at the start and/or end of the interval. If no interval is specified, the markers will be shown at the edge of the graphing area. The default is not to show any markers.

Legend text

Enter a description to show in the legend. If empty the function equation will be used.

Graph properties

You can choose between different line styles for which you want the tangent/normal to be drawn. You can choose between solid, dashed, dotted or a combination of these. You can also choose the width of the tangent/normal. The width is notified in screen pixels. There are also a lot of different colors you can choose between.