HP 48G - Page 22

EQUATION
Pressing [EQUATION) starts the EquationWriter, an
alternate form of command line useful when entering
algebraic expressions or equations. Instead of the
normal command-line approach to expressions (i.e.
usingthe ' expr' format), which relies on hard-to-read
parentheses, the EquationWriter lets you write ex-
pressions in a more familiar textbook (“chalkboard”)
form. So,instead of ' 1J L 3*A*E+4=B*Z 1-5=HYFP '
!
Note, however, that this formatiis for your eyes only—
and only while you’re working with this command line.
When you press ENTER), the finished algebraic expres-
sion will take its place on the stack in the usual ' expr'
syntax, parentheses and all.
for example, you'll instead see —SHyp .
The mostimportantkey when usingthe EquationWriter
is (»]. When building an expression, you must use (»]
to move to the next “component” of the expression.
That is, you use (») to exit a denominator or get “out-
side” a set of parentheses, a radical sign, an expo-
nent, etc. Example: Use the EquationWriter to enter
L SHyp
Start the EquationWriter: (<5JEQUATION). The stack
disappears (but notthe menu key labels). Now watch
your screen as you do these keystrokes:
BFABOENOEFAB 000 EENOOIENE
Notice how (»)(»)(»] exits first the final exponent, then
the radical, then the denominator. Note also that you
can use implied multiplication (i.e. omit the key-
stroke) with single-letter variable names only. When
you're ready, sends the expressionto the stack
(just like the other, “normal” command line). There
the algebraic object appears in its usual line format:
VLl CAEAME RN 1 -0xHYP
To edit an algebraic expression already on the stack,
you could press (GJEDIT), as usual, to send it to the
normal command line. But to send it instead to the
EquationWriter, press (or just (v)) instead.*
([ VEW] is like (q]EDIT), only smarter: Depending on the type of object,
‘—[VEW sends it either to the EquationWriter (for algebraics), the Matrix
Writer (for arrays), or to the normal command line (for most other types).
20 THE HP 48G/GX Pocker GuIDE