Texas Instruments TITANIUM TI-89 - Manual (Page 910)

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) ¸
5м 5ш 2+(3м 5ш 2)ш i
¥¸ л 2.071…м 4.071…ш 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) ¸
2øy 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_)