DIFFERENTIATE2
The DIFFERENTIATE2 function is used exactly like the DIFFERENTIATE function. The only difference is that DIFFERENTIATE2 uses quadratic interpolation whereas the DIFFERENTIATE function uses cubic interpolation in the process of differentiating the data in the table. A warning message will be generated if the command attempts to extrapolate data. Warnings will not be visible unless the Display Warning Messages control in the Options tab of the Preferences dialog is checked.