Texas Instruments PLUS TI-89 - Manual (Page 60)

Chapter 2: Operating the Calculator 43
02OPER DOC TI-89/TI-92 Plus: Operating the TI-89/TI-92 Plus (English) Susan Gullord Revised: 02/23/01 1:06 PM Printed: 02/23/01 2:11 PM Page 43 of 44
From the Home screen, display the Clean Up menu by pressing:
TI . 89: 2 ˆ
TI . 92 Plus: ˆ
Menu Item Description
Clear a–z Clears (deletes) all single-character variable names
in the current folder, unless the variables are locked
or archived. You will be prompted to press ¸ to
confirm the action.
Single-character variable names are often used in
symbolic calculations such as:
solve(a ø x ñ +b ø x+c=0,x)
If any of the variables have already been assigned a
value, your calculation may produce misleading
results. To prevent this, you can select
1:Clear a–z
before beginning the calculation.
NewProb Places NewProb in the entry line. You must then
press ¸ to execute the command.
NewProb performs a variety of operations that let you
begin a new problem from a cleared state without
resetting the memory:
¦ Clears all single-character variable names in the
current folder (same as
1:Clear a–z ), unless the
variables are locked or archived.
¦ Turns off all functions and stat plots ( FnOff and
PlotsOff ) in the current graphing mode.
¦ Performs ClrDraw , ClrErr , ClrGraph , ClrHome ,
ClrIO , and ClrTable .
Restore
custom
default If a custom menu other than the default is in effect,
this lets you restore the default. Refer to page 37.
Using the Clean Up Menu to Start a New Problem
On the Home screen, the Clean Up toolbar menu lets you start
a new calculation from a cleared state without resetting the
TI - 89 / TI - 92 Plus’s memory.
Clean Up Toolbar
Menu
Tip: When defining a
variable that you want to
retain, use more than one
character in the name. This
prevents it from being
deleted inadvertently by
1:Clear a–z
.
Note: For information about
checking and resetting
memory or other system
defaults, refer to
Chapter 21.