Texas Instruments Titanium TI-89, Руководство пользователя

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766 Appendix A: Functions and Instructions
ans()
2 ±
key
ans()
⇒
value
ans( integer )
⇒
value
Returns a previous answer from the Home screen
history area.
integer
, if included, specifies which previous answer
to recall. Valid range for
integer
is from 1 to 99 and
cannot be an expression. Default is 1, the most
recent answer.
To use
ans()
to generate the Fibonacci
sequence on the Home screen, press:
1 ¸ 1
1 ¸ 1
2 ± « 2 ± A 0
2
¸
2
¸
3
¸
5
approx()
MATH/Algebra menu
approx(
expression
)
⇒
value
Returns the evaluation of
expression
as a decimal
value, when possible, regardless of the current
Exact/Approx
mode.
This is equivalent to entering
expression
and
pressing
¥ ¸
on the Home screen.
approx( p ) ¸ 3.141 ...
approx(
list1
)
⇒
list
approx(
matrix1
)
⇒
matrix
Returns a list or matrix where each element has
been evaluated to a decimal value, when possible.
approx({sin(
p
),cos(
p
)})
¸
{0.
ë
1.}
approx([ ‡ (2), ‡ (3)]) ¸
[1.414 ... 1.732 ... ]
Archive
CATALOG
Archive
var1 [, var2] [, var3] …
Moves the specified variables from RAM to the user
data archive memory.
You can access an archived variable the same as
you would a variable in RAM. However, you cannot
delete, rename, or store to an archived variable
because it is locked automatically.
To unarchive variables, use
Unarchiv
.
10
!
arctest
¸
10
Archive arctest
¸
Done
5
ù
arctest
¸
50
15 ! arctest ¸
N
Unarchiv arctest ¸ Done
15
!
arctest
¸
15
arcLen()
MATH/Calculus menu
arcLen(
expression1
,
var
,
start
,
end
)
⇒
expression
Returns the arc length of expression1 from start to
end with respect to variable var .
Regardless of the graphing mode, arc length is
calculated as an integral assuming a function mode
definition.
arcLen(cos(x),x,0,
p
)
¸
3.820 ...
arcLen(f(x),x,a,b) ¸
⌡
⌠
a
b
(
d
d
x
(f(x)))
ñ
+1
d
x
arcLen( list1,var,start,end )
⇒
list
Returns a list of the arc lengths of each element of
list1 from start to end with respect to var.
arcLen({sin(x),cos(x)},x,0,
p
)
{3.820 ... 3.820 ... }
augment()
MATH/Matrix menu
augment(
list1, list2
)
⇒
list
Returns a new list that is
list2
appended to the end
of
list1
.
augment({1,
ë
3,2},{5,4})
¸
{1 ë 3 2 5 4}