Texas Instruments Titanium TI-89, User Manual

Page: 254 / 977

Symbolic Manipulation 251
Finding Proper Fractions and Common Denominators
Use the
propFrac
(
„
7
) and
comDenom
(
„
6
) functions.
In this example:
Find a proper fraction for the expression
(
x
4
N 2x
2
+ x) / (2x
2
+ x + 4)
.
Then transform the answer into a ratio of a
fully expanded numerator and a fully
expanded denominator.
Notice that
propFrac
and
comDenom
perform
opposite operations.
Note:
You can use
comDenom
with an
expression, list, or matrix.
propFrac( rational expression
[,
var
]
)
for proper fractions with respect
to a variable
comDenom( expression
[,
var
]
)
for common denominators that collect
similar powers of this variable
If you do this example
on your handheld, the
propFrac function
scrolls off the top of the
screen.