Texas Instruments TITANIUM TI-89 - Manual (Page 253)

Symbolic Manipulation 253
Specifying Domain Constraints Specifying Domain Constraints Specifying Domain Constraints Specifying Domain Constraints
Many identities and transformations are valid for only a particular domain. For example:
Use the “ with ” operator to specify the domain constraint.
- Substituting for more general
expressions (either
m
ø
c
2
=e
or c
2 ø
m=e ) may not work as you
anticipate.
Note: Use the solve function to help determine
the single-variable substitution.
ln(x † y) = ln(x) + ln(y) only if x and/or y is
not negative
Sin
- 1(sin(
q )) = q
only if q ‚ Lp /2 and q
 p /2 radians
Because ln(x † y) = ln(x) + ln(y) is not always valid,
the logarithms are not combined.
With a constraint, the identity is valid and the
expression is simplified.
No match for
substitution