Ans(), Approx(), Archive – Texas Instruments PLUS TI-89 User Manual
Page 433: Arclen()
416 Appendix A: Functions and Instructions
8992APPA.DOC TI-89 / TI-92 Plus: Appendix A (US English) Susan Gullord Revised: 02/23/01 1:48 PM Printed: 02/23/01 2:21 PM Page 416 of 132
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. ë1.}
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
5ùarctest ¸
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
dx
(f(x)))ñ+1 dx
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...}