Texas Instruments Titanium TI-89, Руководство пользователя, Страница: 779 / 977

776 Appendix A: Functions and Instructions
csc
L
1
()
MATH/Trig menu
csc -1 ( expression1 )
⇒
expression
csc -1 ( list1 )
⇒
list
Returns the angle whose cosecant is expression1or
returns a list containing the inverse cosecants of
each element of
list1.
Note: The result is returned as either a degree or
radian angle, according to the current angle mode.
In Degree angle mode:
csc
L 1
(1)
¸
90
In Radian angle mode:
csc
L 1
({1,4,6})
¸
p
2
sin
L 1
(1/4) sin
L 1
(1/6)
csch()
MATH/Hyperbolic menu
csch( expression1 )
⇒
expression
csch( list1 )
⇒
list
Returns the hyperbolic cosecant of expression1 or
returns a list of the hyperbolic cosecants of all
elements of
list1.
csch(3)
¸
1
sinh(3)
csch({1,2.1,4})
¸
1
sinh(1)
.248…
1
sinh(4)
csch
L
1
()
MATH/Hyperbolic menu
csch
L 1
(
expression1
)
⇒
expression
csch
L 1
(
list1
)
⇒
list
Returns the inverse hyperbolic cosecant of
expression1 or returns a list containing the inverse
hyperbolic cosecants of each element of
list1.
csch
L
1
(1)
¸
sinh
-1
(1)
csch
L
1
({1,2.1,3})
¸
sinh
L
1
(1) .459… sinh
L 1
(1/3)
cSolve()
MATH/Algebra/Complex menu
cSolve(
equation
,
var
)
⇒
Boolean expression
Returns candidate complex solutions of an equation
for
var
. The goal is to produce candidates for all real
and non-real solutions. Even if
equation
is real,
cSolve()
allows non-real results in real mode.
Although the TI-89 Titanium/Voyage™ 200
processes all undefined variables that do not end
with an underscore (_) as if they were real,
cSolve()
can solve polynomial equations for complex
solutions.
cSolve(x^3=
ë
1,x)
¸
solve(x^3=
ë
1,x)
¸
cSolve()
temporarily sets the domain to complex
during the solution even if the current domain is
real. In the complex domain, fractional powers
having odd denominators use the principal rather
than the real branch. Consequently, solutions from
solve()
to equations involving such fractional
powers are not necessarily a subset of those from
cSolve()
.
cSolve(x^(1/3)=
ë
1,x)
¸
false
solve(x^(1/3)= ë 1,x) ¸ x = ë 1
cSolve()
starts with exact symbolic methods.
Except in
EXACT
mode,
cSolve()
also uses
iterative approximate complex polynomial factoring,
if necessary.
Note: See also
cZeros()
,
solve()
, and
zeros()
.
Note: If
equation
is non-polynomial with functions
such as
abs()
,
angle()
,
conj()
,
real()
, or
imag()
,
you should place an underscore _
@
¥ q
H
2 q
) at the end of
var
. By default, a
variable is treated as a real value.
Display
Digits
mode in
Fix 2
:
exact(cSolve(x^5+4x^4+5x
^3 ì 6x ì 3=0,x)) ¸
cSolve(ans(1),x)
¸
If you use
var
_ , the variable is treated as complex.
z is treated as real: