Texas Instruments Titanium TI-89, Руководство пользователя

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808 Appendix A: Functions and Instructions
isClkOn()
CATALOG
isClkOn()
⇒
true,false
Determines if the clock is
ON
or
OFF
. Returns
true
if the clock is
ON
. Returns
false
if the clock is
OFF
.
isPrime()
MATH/Test menu
isPrime(
number
)
⇒
Boolean constant expression
Returns true or false to indicate if
number
is a whole
number
‚
2 that is evenly divisible only by itself and
1.
If
number
exceeds about 306 digits and has no
factors
c
1021,
isPrime( number )
displays an error
message.
If you merely want to determine if
number
is prime,
use
isPrime()
instead of
factor()
. It is much faster,
particularly if
number
is not prime and has a second-
largest factor that exceeds about five digits.
IsPrime(5)
¸
true
IsPrime(6) ¸ false
Function to find the next prime after a specified
number:
Define nextPrim(n)=Func:Loop:
n+1
! n:if isPrime(n):return n:
EndLoop:EndFunc
¸
Done
nextPrim(7) ¸ 11
Item
CATALOG
Item
itemNameString
Item
itemNameString
,
label
Valid only within a
Custom...EndCustm
or
ToolBar...EndTBar
block. Sets up a drop-down
menu element to let you paste text to the cursor
position (
Custom
) or branch to a label (
ToolBar
).
Note: Branching to a label is not allowed within a
Custom
block.
See
Custom
example.
Lbl
CATALOG
Lbl labelName
Defines a label with the name
labelName
in the
program.
You can use a
Goto
labelName
instruction to
transfer program control to the instruction
immediately following the label.
labelName
must meet the same naming
requirements as a variable name.
Program segment:
©
:Lbl lbl1
:InputStr "Enter password",
str1
:If str1
ƒ
password
: Goto lbl1
:Disp "Welcome to ..."
©
lcm()
MATH/Number menu
lcm(
number1
,
number2
)
⇒
expression
lcm(
list1
,
list2
)
⇒
list
lcm(
matrix1
,
matrix2
)
⇒
matrix
Returns the least common multiple of the two
arguments. The
lcm
of two fractions is the
lcm
of
their numerators divided by the
gcd
of their
denominators. The
lcm
of fractional floating-point
numbers is their product.
For two lists or matrices, returns the least common
multiples of the corresponding elements.
lcm(6,9)
¸
18
lcm({1/3,
ë
14,16},{2/15,7,5})
¸
{2/3 14 80}