Texas Instruments TITANIUM TI-89 - Manual (Page 796)

796 Appendix A: Functions and Instructions
cos ê () ¥ R key
cos ê ( expression1 )
⇒ ⇒ ⇒ ⇒ expression
cos ê ( list1 ) ⇒ ⇒ ⇒ ⇒ list
cos ê ( expression1 ) returns the angle whose cosine
is expression1 as an expression.
cos ê ( list1 ) returns a list of the inverse cosines of
each element of list1 .
Note: The result is returned as a degree, gradian
or radian angle, according to the current angle
mode setting.
In Degree angle mode:
cosê (1) ¸ 0
In Gradian angle mode:
cosê (0) ¸ 100
In Radian angle mode:
cosê ({0,.2,.5}) ¸
{
p
2
1.369 ... 1.047 ...
}
cos ê( squareMatrix1 )
⇒ ⇒ ⇒ ⇒ squareMatrix
Returns the matrix inverse cosine of squareMatrix1 .
This is not the same as calculating the inverse
cosine of each element. For information about the
calculation method, refer to
cos() .
squareMatrix1 must be diagonalizable. The result
always contains floating-point numbers.
In Radian angle mode and Rectangular complex
format mode:
cosê([1,5,3;4,2,1;6,л2,1]) ]) ]) ])
¸





 1.734…+.064…ш i л 1.490…+2.105…ш i …
л .725…+1.515…ш i .623…+.778…ø i …
л 2.083…+2.632…ш i 1.790…м 1.271…ш i …
cosh()
MATH/Hyperbolic menu
cosh( expression1 ) ⇒ ⇒ ⇒ ⇒ expression
cosh( list1 )
⇒ ⇒ ⇒ ⇒ list
cosh ( expression1 ) returns the hyperbolic cosine
of the argument as an expression.
cosh ( list1 ) returns a list of the hyperbolic cosines
of each element of list1 .
cosh(1.2) ¸ 1.810 ...
cosh({0,1.2}) ¸ {1 1.810 ... }
cosh( squareMatrix1 )
⇒ ⇒ ⇒ ⇒ squareMatrix
Returns the matrix hyperbolic cosine of
squareMatrix1 . This is not the same as calculating
the hyperbolic cosine of each element. For
information about the calculation method, refer
to
cos() .
squareMatrix1 must be diagonalizable. The result
always contains floating-point numbers.
In Radian angle mode:
cosh([1,5,3;4,2,1;6,ë2,1])
¸





 421.255 253.909 216.905
327.635 255.301 202.958
226.297 216.623 167.628
cosh ê ()
MATH/Hyperbolic menu
cosh ê ( expression1 )
⇒ ⇒ ⇒ ⇒ expression
cosh ê ( list1 ) ⇒ ⇒ ⇒ ⇒ list
cosh ê ( expression1 ) returns the inverse hyperbolic
cosine of the argument as an expression.
cosh ê ( list1 ) returns a list of the inverse
hyperbolic cosines of each element of list1 .
coshê (1) ¸ 0
coshê ({1,2.1,3}) ¸
{0 1.372
...
coshê (3)}
cosh ê( squareMatrix1 ) ⇒ ⇒ ⇒ ⇒ squareMatrix
Returns the matrix inverse hyperbolic cosine of
squareMatrix1 . This is not the same as calculating
the inverse hyperbolic cosine of each element. For
information about the calculation method, refer
to
cos() .
squareMatrix1 must be diagonalizable. The result
always contains floating-point numbers.
In Radian angle mode and Rectangular complex
format mode:
coshê([1,5,3;4,2,1;6,л2,1]) ¸





 2.525…+1.734…ш i л.009…м 1.490…ш i …
.486…м.725…ш i 1.662…+.623…ø i …
л .322…м 2.083…ш i 1.267…+1.790…ø i …