Texas Instruments TI-89 Titanium User Manual page 886

¡, ', "
2 "
key (¡),
⇒
dd ¡ mm ss.ss
' "
A positive or negative number
dd
A non-negative number
mm
A non-negative number
ss.ss
Returns
dd
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.
'
2 È key
(prime)
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.
_ @
(underscore) ¥
expression _ unit
Designates the units for an
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
H ¥ À
to select units from a menu, or you can type the
unit names directly.
variable _
When
variable
though it represents a complex number. By
default, without the _ , the variable is treated as
real.
If
variable
retains its original data type.
variable
Note: You can store a complex number to a
variable without using _ . However, for best
results in calculations such as
, the _ is recommended.
cZeros()
Appendix A: Functions and Instructions
2 È 2 É
key ('),
expression
+( /60)+( /3600).
mm ss.ss
H
2
key
. All unit
expression
9
has no value, it is treated as
has a value, the _ is ignored and
cSolve()
key (")
In Degree angle mode:
25°13'17.5" ¸
25°30' ¸
deSolve(y''=y^(ë 1/2) and
y(0)=0 and y'(0)=0,t,y) ¸
key
3_m 4 _ft ¸
Note: To type 4, press 2 .
Assuming z is undefined:
real(z) ¸
real(z_) ¸
imag(z) ¸
imag(z_) ¸
and
25.221 ...
51/2
2øy
3/4
=t
3
9.842...ø_ft
z
real(z_)
0
imag(z_)
883