796
Appendix A: Functions and Instructions
For the
AUTO
setting of the
Exact/Approx
mode,
including
var
permits approximation with floating-
point coefficients where irrational coefficients cannot
be explicitly expressed concisely in terms of the
built-in functions. Even when there is only one
variable, including
var
might yield more complete
factorization.
Note:
See also
comDenom()
for a fast way to
achieve partial factoring when
factor()
is not fast
enough or if it exhausts memory.
Note:
See also
cFactor()
for factoring all the way to
complex coefficients in pursuit of linear factors.
factor(x^5+4x^4+5x^3
ì
6x
ì
3)
¸
x
5
+
4
ø
x
4
+
5
ø
x
3
ì
6
ø
x
ì
3
factor(ans(1),x)
¸
(x
ì
.964…)
ø
(x
+.611…)
ø
(x
+
2.125…)
ø
(x
ñ
+
2.227…
ø
x
+
2.392…)
factor(
rationalNumber
)
returns the rational number
factored into primes. For composite numbers, the
computing time grows exponentially with the
number of digits in the second-largest factor. For
example, factoring a 30-digit integer could take
more than a day, and factoring a 100-digit number
could take more than a century.
Note:
To stop (break) a computation, press
´
.
If you merely want to determine if a number is
prime, use
isPrime()
instead. It is much faster,
particularly if
rationalNumber
is not prime and if the
second-largest factor has more than five digits.
factor(152417172689)
¸
123457
ø
1234577
isPrime(152417172689)
¸
false
Fill
MATH/Matrix menu
Fill
expression, matrixVar
⇒
matrix
Replaces each element in variable
matrixVar
with
expression
.
matrixVar
must already exist.
[1,2;3,4]
!
amatrx
¸
[
1 2
3 4
]
Fill 1.01,amatrx
¸
Done
amatrx
¸
[
1.01 1.01
1.01 1.01
]
Fill
expression, listVar
⇒
list
Replaces each element in variable
listVar
with
expression
.
listVar
must already exist.
{1,2,3,4,5}
!
alist
¸
{1 2 3 4 5}
Fill 1.01,alist
¸
Done
alist
¸
{1.01 1.01 1.01 1.01 1.01}
floor()
MATH/Number menu
floor(
expression
)
⇒
integer
Returns the greatest integer that is
c
the argument.
This function is identical to
int()
.
The argument can be a real or a complex number.
floor(
ë
2.14)
¸
ë
3.
floor(
list1
)
⇒
list
floor(
matrix1
)
⇒
matrix
Returns a list or matrix of the floor of each element.
Note:
See also
ceiling()
and
int()
.
floor({3/2,0,
ë
5.3})
¸
{1 0
ë
6.}
floor([1.2,3.4;2.5,4.8])
¸
[
1. 3.
2. 4.
]
fMax()
MATH/Calculus menu
fMax(
expression, var
)
⇒
Boolean expression
Returns a Boolean expression specifying candidate
values of
var
that maximize
expression
or locate its
least upper bound.
fMax(1
ì
(x
ì
a)^2
ì
(x
ì
b)^2,x)
¸
x =
a+b
2
fMax(.5x^3
ì
x
ì
2,x)
¸
x =
ˆ
Summary of Contents for Titanium TI-89
Page 9: ...Getting Started 6 TI 89 Titanium keys Ë Ì Í Ê ...
Page 34: ...Getting Started 31 2 or D 2 B u s i n e s s D B D B Press Result ...
Page 43: ...Getting Started 40 3 0 D B D D B D Press Result ...
Page 44: ...Getting Started 41 D 2 0 0 2 D B Scroll down to October and press Press Result ...
Page 58: ...Getting Started 55 Example Set split screen mode to TOP BOTTOM Press Result 3 B D ...
Page 70: ...Getting Started 67 ...
Page 175: ...Operating the Calculator 172 From the Keyboard ...
Page 456: ...Tables 453 ...
Page 527: ...Data Matrix Editor 524 ...
