Texas Instruments TI-89 Manuale Utente
Symbolic Manipulation
254
Note:
Enter
ln(x
†
y)
instead of
ln(xy)
; otherwise, xy is interpreted as a single variable
named xy.
Note:
For ‚ or , press 8 Ã or 8 Â. You can also use 2 I
8
or
2 G
2
to
select them from a menu.
Using Substitutions vs. Defining a Variable
Using Substitutions vs. Defining a Variable
Using Substitutions vs. Defining a Variable
Using Substitutions vs. Defining a Variable
However, substitution is preferable for most cases because the variable is defined only
for the current calculation and does not accidentally affect later calculations.
for the current calculation and does not accidentally affect later calculations.
Because sin
L1
(sin(
q
)) =
q
is not always valid, the
expression is not simplified.
With a constraint, the expression can be simplified.
In many cases, you can achieve the same
effect as a substitution by defining the
variable.
effect as a substitution by defining the
variable.
Substituting x=1 does not affect the next
calculation.
calculation.