Texas Instruments TI-89 Voyage 200, Руководство пользователя

Страница: 821 / 1008

Appendix A: Functions and Instructions 821
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
Use the “|” operator to restrict the solution
interval and/or specify the sign of other undefined
variables.
For the
APPROX
setting of the
Exact/Approx
mode,
fMax()
iteratively searches for one
approximate local maximum. This is often faster,
particularly if you use the “|” operator to
constrain the search to a relatively small interval
that contains exactly one local maximum.
Note: See also
fMin()
and
max()
.
fMax(.5x^3
ì
x
ì
2,x)|x

1
¸
x =
ë
.816
...
fMax(a
ù
x^2,x)
¸
x =
ˆ
or x =
ë
ˆ
or x = 0 or a = 0
fMax(a
ù
x^2,x)|a<0
¸
x = 0
fMin()
MATH/Calculus menu
fMin(
expression, var
)
⇒
⇒ ⇒
⇒
Boolean expression
Returns a Boolean expression specifying
candidate values of
var that minimize expression or
locate its greatest lower bound.
Use the “|” operator to restrict the solution
interval and/or specify the sign of other undefined
variables.
For the
APPROX
setting of the
Exact/Approx
mode,
fMin()
iteratively searches for one
approximate local minimum. This is often faster,
particularly if you use the “|” operator to
constrain the search to a relatively small interval
that contains exactly one local minimum.
Note: See also
fMax()
and
min()
.
fMin(1
ì
(x
ì
a)^2
ì
(x
ì
b)^2,x)
¸
x =
ˆ
or x =
ë
ˆ
fMin(.5x^3
ì
x
ì
2,x)|x
‚
1
¸
x = 1
fMin(a
ù
x^2,x)
¸
x =
ˆ
or x =
ë ˆ
or x = 0 or a = 0
fMin(a
ù
x^2,x)|a>0 and x>1
¸
x = 1.
fMin(a
ù
x^2,x)|a>0
¸
x = 0
FnOff
CATALOG
FnOff
Deselects all Y= functions for the current
graphing mode.
In split-screen, two-graph mode,
FnOff
only
applies to the active graph.
FnOff [1] [, 2] ... [,99]
Deselects the specified Y= functions for the
current graphing mode.
In function graphing mode:
FnOff 1,3
¸
deselects
y1(x)
and
y3(x)
.
In parametric graphing mode:
FnOff 1,3 ¸
deselects
xt1(t)
,
yt1(t)
,
xt3(t)
, and
yt3(t)
.