The real beauty of math boxes in the TI-Nspire Notes application is their ability to seamlessly interact with other applications. In this investigation, you are going to use a Notes page to interact with a Graphs page.

Here are the steps to follow to set up the split page:

Insert a Notes page. Press [CTRL][I]→Add Notes.

Split the screen. Press [DOC]→Page Layout→Select Layout and choose the side-by-side option.

Move your cursor to the Press Menu message and press [CLICK] to make that side of the screen active; then press [MENU]→Add Graphs.

Math boxes can be used to define variables and functions (and anything else that you can do on a calculator page). Because you want to use the slope formula, define the variables *x1**,* *y1**,* *x2**,* and *y2**.* Use separate math boxes (**[CTRL][****M]**) and type **x1:=3**, **y1:=4**, **x2:=-6**, and **y2:=-2** to define the variables.

On the Graphs page, place a point on the graph. Right-click, **[CTRL][MENU]**→Coordinates and Equations. Move your cursor over the *x*-coordinate and right-click, **[CTRL][MENU]**→Variables→Link To→*x1*. See the first screen. Link the *y*-coordinate to *y1**,* and repeat the process to place another point linked to *x2* and *y2**.* Use the Line tool to construct a line that connects the two points.

Insert another math box and define *m* using the slope formula. See the second screen. Do you notice how the slope displays nicely as a simplified fraction? Try clicking in a math box and changing the value of *x1**.* The slope automatically updates! See the third screen. The Graphs page also updates when the variables are changed.

Notes with interactive math boxes provide a dynamic way to display calculations. Math boxes can be used to interact with many other applications as well. Explore the possibilities.

A program can be activated using a math box on a Notes page. Because of the dynamic nature of Notes with interactive math boxes, the program continually runs while the document is open. Advanced authors on the TI-Nspire use this feature to create some really intense documents.