HP Prime Graphing NW280AAABA manual Referencing variables

Referencing variables

Any variable can be inserted in a cell. This includes Home variables, App variables, CAS variables and user variables.

Variables can be referenced or entered. For example, if you have assigned 10 to P in Home view, you could enter =P*5 in a spreadsheet cell, press Eand get 50. If you subsequently changed the value of P, the value in that cell automatically changes to reflect the new value. This is an example of a referenced variable.

If you just wanted the current value of P and not have the value change if P changes, just enter P and press E. This is an example of an entered variable.

Variables given values in other apps can also be referenced in a spreadsheet. In chapter 13 we see how the Solve app can be used to solve equations. An example used is V 2 = U 2 + 2AD. You could have four cells in a spreadsheet with =V, =U, =A, and =D as formulas. As you experiment with different values for these variables in the Solve app, the entered and the calculated values are copied to the spreadsheet (where further manipulation could be done).

The variables from other apps includes the results of certain calculations. For example, if you have plotted a function in the Function app and calculated the signed area between two x- values, you can reference that value in a spreadsheet by

pressing a, tapping , and then selecting Function > Results > SignedArea.

Numerous system variables are also available. For example, you could enter S+Eto get the last answer calculated in Home view. You could also enter S.S+E to get the last answer calculated in Home view and have the value automatically updated as new calculations are made in Home view. (Note that this works only with the Ans from Home view, not the Ans from CAS view.)

All the variables available to you are listed on the variables menus, displayed by pressing a. A comprehensive list of these variables is provided in chapter 22, “Variables”, beginning on page 423.

Spreadsheet 205