HP 95LX - Page 56

Using Hidden Variables
When you get proficient with writing Solver formulas, you may wish to put
together more complex calculation templates (see pages 58-62 for some examples).
To aid you in your efforts, you can use two functions that allow you to create
intermediate, hidden variables—to shorten the amount of typing you need and to
minimize confusion in complex equations. The two special functions are Let and
Get—abbreviated as L() and G().
For example, suppose you need to use the following expression over and over in a
long equation: {BeginYalue-EndYalue) #ofYalues. Tosave your-
self a lot of typing, you can assign that expression a name—say, \*—with the Let
function. To do this, on the first time you need the expression in the question,
instead of typing just the expression, you type this:
L{v,{BeginVYalue-EndYalue) #ofVYalues)
Then, each time you need to use the expression thereafter, you can simply use the
variable name, V, asin A+W/2. Or—ifyou don’t want Wto appear on the menu—
you can use the Get function, as in A+G{yw>~2.
Using the Typing Aids for Solver Functions
Most of the Solver functions are contained in the menus at the bottom of the
equation editing screen. They are used to shorten the typing involved in creating
equations. An example:
1. Move to a Solve Catalog, put the cursor over on the equation side, and press
to display the equation editing screen.
2. Press (SBIR) to bring up a menu of financial Solver functions.
3. Press (F8)(Elds®). You will see SPPY( 4) inserted at the cursor. The cursor
is now waiting for you to enter the first argument for the SPPV function (the
periodicinterest rate). To find out what arguments each function expects, look
at the table on page 150.
56 2. ANALYZING INFORMATION