Texas Instruments TI-89 Titanium User Manual page 851

ShowStat
CATALOG
ShowStat
Displays a dialog box containing the last computed
statistics results if they are still valid. Statistics
results are cleared automatically if the data to
compute them has changed.
Use this instruction after a statistics calculation,
such as
LinReg
sign()
MATH/Number menu
) ⇒
expression1
sign(
) ⇒
list1 list
sign(
) ⇒
matrix1
sign(
For real and complex
expression1
Returns 1 if
Returns ë 1 if
returns „1 if the complex format mode is
sign(0)
; otherwise, it returns itself.
REAL
represents the unit circle in the complex
sign(0)
domain.
For a list or matrix, returns the signs of all the
elements.
simult()
MATH/Matrix menu
coeffMatrix
simult(
Returns a column vector that contains the solutions
to a system of linear equations.
coeffMatrix
coefficients of the equations.
constVector
(same dimension) as
constants.
Optionally, any matrix element is treated as zero if
its absolute value is less than
used only if the matrix has floating-point entries and
does not contain any symbolic variables that have
not been assigned a value. Otherwise,
• If you use ¥ ¸ or set the mode to
Exact/Approx=APPROXIMATE
are done using floating-point arithmetic.
• If
is omitted or not used, the default tolerance
tol
is calculated as:
ë 14 ù max(dim(
5
E
ù rowNorm(
848
.
expression
matrix
, returns
expression1
/ when
expression1 expression1
abs( )
is positive.
expression1
is negative.
expression1
) ⇒
constVector [ tol ] matrix
, ,
must be a square matrix that contains the
must have the same number of rows
and contain the
coeffMatrix
. This tolerance is
tol
, computations
coeffMatrix
))
coeffMatrix
)
{1,2,3,4,5}! L1 ¸ {1 2 3 4 5}
{0,2,6,10,25}! L2 ¸
TwoVar L1,L2 ¸
ShowStat ¸
sign(ë 3.2) ¸
sign({2,3,4,ë 5}) ¸
ƒ 0.
sign(1+abs(x)) ¸
If complex format mode is
sign([ë 3,0,3]) ¸
Solve for x and y:
simult([1,2;3,4],[1;ë 1]) ¸
The solution is x=ë 3 and y=2.
Solve: ax + by = 1
cx + dy = 2
[a,b;c,d]! matx1 ¸
simult(matx1,[1;2]) ¸
is ignored.
tol
Appendix A: Functions and Instructions
{0 2 6 10 25}
ë 1.
1 ë 1}
{1 1
1
:
REAL
[ë 1 „1 1]
x + 2y = 1
3x + 4y = ë 1
ë 3
[ ]
2
a b
[ ]
c d
 
ë (2ø bì d)
 
aø dì bø c
 
2ø aì c
 
aø dì bø c