Texas Instruments TI-89 Voyage 200, User Manual

Page: 893 / 1008

Appendix A: Functions and Instructions 893
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)
Use an
undef
falseResult to define an expression
that graphs only on an interval.
ClrGraph
¸
Graph when(x
‚ ë p
and x<0,x+3,undef)
¸
Omit only the unknownResult to define a two-piece
expression.
Graph when(x<0,x+3,5
ì
x^2)
¸
Nest
when()
to define expressions that have
more than two pieces.
"
ClrGraph
¸
Done
Graph when(x<0,when(x<
ë p
,
4
ù
sin(x),2x+3),5
ì
x^2)
¸