Texas Instruments TI-89 Voyage 200, Руководство пользователя, Страница: 910 / 1008

910 Appendix A: Functions and Instructions
(
magnitude
   
angle
)
⇒ ⇒ ⇒ ⇒
complexValue
(polar input)
Enters a complex value in (r q ) polar form. The
angle
is interpreted according to the current Angle
mode setting.
In Radian angle mode and Rectangular complex
format mode:
5+3
i
ì
(10
p
/4)
¸
5
ì
5
ø
2+(3
ì
5
ø
2)
ø
i
¥¸ ë
2.071…
ì
4.071…
ø
i
¡¡¡¡
, ', "
2 “
key (
¡
),
2 È
key ('),
2 É
key (")
dd ¡¡¡¡ mm
'
ss.ss
"
⇒ ⇒ ⇒ ⇒
expression
dd
A positive or negative number
mm
A non-negative number
ss.ss
A non-negative number
Returns
dd
+(
mm
/60)+(
ss.ss
/3600).
This base-60 entry format lets you:
•
Enter an angle in degrees/minutes/seconds
without regard to the current angle mode.
•
Enter time as hours/minutes/seconds.
In Degree angle mode:
25°13'17.5"
¸
25.221
...
25°30'
¸
51/2
'
(prime) 2 È key
variable
'
variable
''
Enters a prime symbol in a differential equation. A
single prime symbol denotes a 1st-order
differential equation, two prime symbols denote a
2nd-order, etc.
deSolve(y''=y^(
ë
1/2) and y(0)=0 and
y'(0)=0,t,y)
¸
2
ø
y
3/4
3
=t
_
(underscore) ¥  key
expression
_
unit
Designates the units for an expression . All unit
names must begin with an underscore.
You can use pre-defined units or create your own
units. For a list of pre-defined units, refer to the
module about constants and measurement units.
You can press
2
9
to select units from a
menu, or you can type the unit names directly.
3_m
4
_ft
¸
9.842…
ø
_ft
Note: To type
4
, press
2

.
variable
_
When variable has no value, it is treated as though
it represents a complex number. By default,
without the _
, the variable is treated as real.
If
variable
has a value, the _ is ignored and
variable
retains its original data type.
Note: You can store a complex number to a
variable without using _ . However, for best
results in calculations such as
cSolve()
and
cZeros()
, the _ is recommended.
Assuming z is undefined:
real(z)
¸
z
real(z_)
¸
real(z_)
imag(z)
¸
0
imag(z_)
¸
imag(z_)