Texas Instruments Titanium TI-89, Руководство пользователя

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Appendix A: Functions and Instructions 865
unitV()
MATH/Matrix/Vector ops menu
unitV( vector1 )
⇒
vector
Returns either a row- or column-unit vector,
depending on the form of
vector1
.
vector1
must be either a single-row matrix or a
single-column matrix.
unitV([a,b,c])
¸
[
a
a
ñ
+b
ñ
+c
ñ
b
a
ñ
+b
ñ
+c
ñ
c
a
ñ
+b
ñ
+c
ñ
]
unitV([1,2,1])
¸
[
‡
6
6
‡
6
3
‡
6
6
]
unitV([1;2;3])
¸








‡ 14
14
‡
14
7
3
ø ‡
14
14
Unlock
CATALOG
Unlock
var1[, var2][, var3]
...
Unlocks the specified variables.
Note: The variables can be locked using the
Lock
command.
variance()
MATH/Statistics menu
variance(
list
[
, freqlist
]
)
⇒
expression
Returns the variance of
list
.
Each freqlist element counts the number of
consecutive occurrences of the corresponding
element in
list
.
Note:
list
must contain at least two elements.
variance({a,b,c}) ¸
a ñ - a ø (b+c)+b ñ - b ø c+c ñ
3
variance({1,2,5,
ë
6,3,
ë
2})
¸
31/2
variance({1,3,5},{4,6,2}) ¸
68/33
variance(
matrix1
[
, freqmatrix
]
)
⇒
matrix
Returns a row vector containing the variance of
each column in
matrix1
.
Each
freqmatrix
element counts the number of
consecutive occurrences of the corresponding
element in
matrix1
.
Note:
matrix1
must contain at least two rows.
variance([1,2,5;
ë
3,0,1;
.5,.7,3])
¸
[4.75 1.03 4]
variance([
L
1.1,2.2;3.4,5.1;
L 2.3,4.3],[6,3;2,4;5,1]) ¸
[3.91731,2.08411]
when()
CATALOG
when( condition , trueResult [, falseResult ]
[, unknownResult ] )
⇒
expression
Returns
trueResult
,
falseResult
, or
unknownResult
,
depending on whether
condition
is true, false, or
unknown. Returns the input if there are too few
arguments to specify the appropriate result.
Omit both
falseResult
and
unknownResult
to make an
expression defined only in the region where
condition
is true.
when(x<0,x+3)|x=5
¸
when(x<0,3+x)