4444 rect, Ref() – Texas Instruments TITANIUM TI-89 User Manual
Page 863
Appendix A: Functions and Instructions
863
real(
list1
)
⇒
⇒
⇒
⇒
list
Returns the real parts of all elements.
real({a+iù b,3,i})
¸
{a 3 0}
real(
matrix1
)
⇒
⇒
⇒
⇒
matrix
Returns the real parts of all elements.
real([a+iù b,3;c,i])
¸
[
a 3
c 0
]
4444Rect
MATH/Matrix/Vector ops menu
vector
4444Rect
Displays
vector
in rectangular form [x, y, z]. The
vector must be of dimension 2 or 3 and can be a
row or a column.
Note:
4444Rect
is a display-format instruction, not a
conversion function. You can use it only at the
end of an entry line, and it does not update
ans
.
Note: See also
4
Polar
.
[3,pà4,pà6]4Rect
¸
[
3ш ‡2
4
3ш ‡2
4
3ш ‡3
2
]
[a,b,c]
¸
[aø cos(b)ø sin(c)
aø sin(b)ø sin(c) aø cos(c)]
complexValue
4444Rect
Displays
complexValue
in rectangular form a+b
i
.
The
complexValue
can have any complex form.
However, an r
e
i
q
entry causes an error in Degree
angle mode.
Note: You must use parentheses for an (r
q)
polar entry.
In Radian angle mode:
4
e
^(p/3)4Rect ¸
4ø
e
p
3
(4p/3)4Rect ¸ 2+2ш
3
ш
i
In Gradian angle mode:
(1100)4Rect ¸
i
In Degree angle mode:
(460)4Rect ¸ 2+2ш
3333
ш
i
Note: To type
4444Rect
from the keyboard, press
2
for the
4444
operator. To type
, press
2
’
.
ref()
MATH/Matrix menu
ref(
matrix1
[,
tol
]) ⇒
⇒
⇒
⇒
matrix
Returns the row echelon form of
matrix1
.
Optionally, any matrix element is treated as zero
if its absolute value is less than
tol
. This tolerance
is used only if the matrix has floating-point
entries and does not contain any symbolic
variables that have not been assigned a value.
Otherwise,
tol
is ignored.
•
If you use ¥ ¸ or set the mode to
Exact/Approx=APPROXIMATE
, computations
are done using floating-point arithmetic.
•
If
tol
is omitted or not used, the default
tolerance is calculated as:
5
E
л 14 щ max(dim(
matrix1
))
ù rowNorm(
matrix1
)
Note: See also
rref().
ref([л2,л2,0,л6;1,л1,9,л9;л5,
2,4,л4])
¸
1 л 2/5 л 4/5 4/5
0 1 4/7 11/7
0 0 1 л 62/71
[a,b,c;e,f,g]!m1 ¸
[
]
a b c
e f g
ref(m1) ¸
1
f
e
g
e
0 1
aøgì cøe
aøfì bшe