Tangent

When the tangent function is selected, a vertical indicator line will appear. A short tangent line is drawn at the point on the graph crossed by this line. A floating box (helper object) displays the numerical slope at that point. Uncheck the box next to Show on Graph from the Options dialog to hide the helper object from the page. Choose Additional Object Options --> Reveal Hidden Objects from the Options menu to call it back up.

Logger Pro calculates the slope of the tangent by taking a weighted average of the slopes of points around the point of interest.  The number of points is set by you in the File Settings dialog to calculate the derivative.

Points may be selected by moving the mouse along the graph or by pressing the left and right arrow keys on the keyboard.

Select Tangent either by clicking the Tangent button on the toolbar or by selecting the Tangent option from the Analyze Menu.

Turn off the Tangent function by clicking the Tangent button, selecting the Tangent option again, or clicking on the close box of the tangent floating box (helper object).
 
 

Toolbar: 
 

See Also:

How To/Drawing a Tangent at a Data Point