Expreg, Factor(), Appendix a: functions and instructions 819 – Texas Instruments TITANIUM TI-89 User Manual
Page 819
Appendix A: Functions and Instructions
819
ExpReg
MATH/Statistics/Regressions menu
ExpReg
list1, list2
[
, [
list3
] [,
list4, list5
]
]
Calculates the exponential regression and
updates all the system statistics variables.
All the lists must have equal dimensions except
for
list5
.
list1
represents xlist.
list2
represents ylist.
list3
represents frequency.
list4
represents category codes.
list5
represents category include list.
Note:
list1
through
list4
must be a variable name
or c1–c99 (columns in the last data variable
shown in the Data/Matrix Editor).
list5
does not
have to be a variable name and cannot be c1–c99
.
In function graphing mode:
{1,2,3,4,5,6,7,8}! L1
¸
{1
2
...
}
{1,2,2,2,3,4,5,7}! L2
¸
{1 2
...
}
ExpReg L1,L2
¸
Done
ShowStat
¸
¸
Regeq(x)"y1(x)
¸
Done
NewPlot 1,1,L1,L2
¸
Done
¥%
factor()
MATH/Algebra menu
factor(
expression1
[,
var
])
⇒
⇒
⇒
⇒
expression
factor(
list1
[
,var
])
⇒
⇒
⇒
⇒
list
factor(
matrix1
[
,var
])
⇒
⇒
⇒
⇒
matrix
factor(
expression1
) returns
expression1
factored
with respect to all of its variables over a common
denominator.
expression1
is factored as much as possible toward
linear rational factors without introducing new
non-real subexpressions. This alternative is
appropriate if you want factorization with respect
to more than one variable.
factor(a^3ù x^2ì aù x^2ì a^3+a)
¸
aø(a
м
1)ш(a
+
1)ø(x
м
1)ш(x
+
1)
factor(x^2+1)
¸
xñ +
1
factor(x^2ì 4)
¸
(x
м
2)ш (x
+
2)
factor(x^2ì 3)
¸
xс м 3
factor(x^2ì a)
¸
xс м a
factor(
expression1,var
)
returns
expression1
factored with respect to variable
var
.
expression1
is factored as much as possible toward
real factors that are linear in
var
, even if it
introduces irrational constants or subexpressions
that are irrational in other variables.
The factors and their terms are sorted with
var
as
the main variable. Similar powers of
var
are
collected in each factor. Include
var
if
factorization is needed with respect to only that
variable and you are willing to accept irrational
expressions in any other variables to increase
factorization with respect to
var
. There might be
some incidental factoring with respect to other
variables.
factor(a^3ù x^2ì aù x^2ì a^3+a,x)
¸
aø (aс м 1)ш (x
м
1)ш (x
+
1)
factor(x^2ì 3,x)
¸
(x
+
‡
3)ø (x
ì
‡
3)
factor(x^2ì a,x)
¸
(x
+
‡
a)ø (x
ì
‡
a)