HP 49g Graphing Calculator - Manual (Page 148)

Using a variable in a calculation
You can use a variable’s contents in a calculation. To continue the
example on page 7-2, suppose you have stored the acceleration of gravity
in a variable named GRAY and that tlris variable happens to be
represented by (F3)- To multiply the acceleration of gravity by 7, you would
press;
i3) places the variable’s name on the command line. Pressing
causes the variable, and then the entire expression, to be evaluated.
Note that if the variable you want to use is not available when you press
(WR), you must first select the directory in which the variable is stored.
(See “Selecting a directory or variable” on page 7-7.)
User-defined functions
User-defined fimctions are a special type of variable. Like variables, you
give a user-defined fimction a name, and store it for later use.
User-defined fimctions operate in the same way as nonnal functions: that
is, you enter the function name, specify the argument or arguments in
parentheses, and then press (ENTER) or 0(33) to evaluate the fimction. The
difference is that you create the function yourself, and give it a name of
your choosing.
Creating a user-defined Function
The following example illustrates how to create a user-defined function to
evaluate 3co.s(.i”) and store it with the name “F2(0”:
1. Press 0rPEF) to place the DEFINE command on tlie command line.
2. With the cursor between the command’s parentheses, define the
function.
®i)F20©@®003(COS)@(2)2
Note that the name you want to give your function must appear to the
left of the equals sign. You specify the fimction to the right of the
equals sign.
3. Press (BNTER) to define the fimction and store it in the current directory.
In this example, it is stored as “F2”.
Page 7-4 Storing objects