HP 40gs - Manual (Page 258)

15-6 Equation Writer
this case, you have to press to select elements in the
expression.
The following illustration shows how an expression can
be viewed as a tree in the Equation Writer. It illustrates a
tree view of the expression:
Suppose that the cursor is positioned to the right of 3:
• If you press once, the 3 component is selected.
• If you press again, the selection moves up the
tree, with x + 3 now selected.
• If you press again, the selection moves up the
tree, and now the entire expression is selected.
• If you had pressed instead of when the
cursor was positioned to the right of 3, the leaves of
the branch get selected (that is, x + 3).
• If you press again, the selection moves up the
tree, and now the entire expression is selected.
• If you now press , just the numerator is selected.
• If you now press again, the top-most branch
selected (that is, (5x + 3).
• Continue pressing to select each top-most leaf in
turn (5x and then 5).
5x 3 + ( ) x 1 – ( ) ⋅
x 3 +
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# N
! N
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