Greatest Integer Function


The greatest integer function, denoted by int, is defined as follows:

int(x) = greatest integer less than or equal to x

The greatest integer function is found in the catalog.

To obtain a graph of the greatest integer function, press MENU 1 to access the RUN-MAT screen. Press OPTN, press F6 until SKTCH is the F2-option. Press F2 to select SKTCH to select the sketch menu, press 4 to select 4:GRAPH, then press 1: to select 1:Y=. Graph Y= is pasted into the home screen. Enter Y = int(x) as follows:

press CTRL CAT/CAL
press F6 to see I in the alphabet menu
press F5 to select I
press 6 to select 6: Int
press ( X ) EXE

One then obtains the graph shown at the right. In this graph, the steps of the int function are inappropriately connected.

To obtain a correct graph, we must change the graph style. Press ESC to return to the home screen. Press CTRL SETUP and change the Draw Type to Plot, then press EXE. Press option and repeat the sketch procedure and you get the graph shown at right.

For a better view, press F2 to access the Zoom menu, then press 7 to select 7: Square. From the zoom square presentation, press F2 to access the Zoom menu again, then press 3 to select 3:In to zoom in. If needed, use the thumb pad arrow keys to place the cursor at the origin, then press EXE to obtain the graph displayed at the right. Note that the step from 0 £ x < 1 is occluded by the x-axis. Press CTRL 0 to toggle on and off the graph menu at the bottom of the screen.