Ans(), Approx(), Archive – Texas Instruments TITANIUM TI-89 User Manual
Page 788: Arclen(), 788 appendix a: functions and instructions
788
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
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
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
...
}