How To Modify An Expression - HP 40gs User Manual

How to modify an expression

Equation Writer
If you're typing an expression, the
to erase what you've typed. If you're selecting, you can:
•
Cancel the selection without deleting the expression
by pressing
deselected portion.
•
Replace the selection with an expression, just by
typing the desired expression.
•
Transform the selected expression by applying a CAS
function to it (which you can invoke from one of CAS
menus along the bottom of the screen).
•
Delete the selected expression by pressing:
•
Delete a selected unary operator at the top of the
expression tree by pressing:
For example, to replace SIN(expr) with COS(expr),
select SIN(expr), press
COS.
•
Delete a binary infix operator and one of its
arguments by selecting the argument you want delete
and pressing:
For example, if you have the expression 1+2 and
select 1, pressing
only 2. Similarly, to delete F(x)= in the expression F(x)
2
= x – x +1, you select F(x) and then press
. This produces x = x
•
Delete a binary operator by selecting:
from the
•
Copy an element from CAS history. You access CAS
history by pressing
details.
. The cursor moves to the end of the
deletes 1+ and leaves
2
– x +1.
Edit expr.
menu and then making the correction.
. See page 15-19 for
key enables you
and then press
15-11