Texas Instruments PLUS TI-89 - Manual (Page 453)

436 Appendix A: Functions and Instructions
8992APPA.DOC TI-89 / TI-92 Plus: Appendix A (US English) Susan Gullord Revised: 02/23/01 1:48 PM Printed: 02/23/01 2:21 PM Page 436 of 132
deSolve( 2ndOrderOde and boundaryCondition1 and
boundaryCondition2 , independentVar ,
dependentVar ) ⇒ a particular solution
Returns a particular solution that satisfies
2ndOrderOde and has specified values at two
different points.
deSolve(w''ì 2w'/x+(9+2/x^2)w=
xù e^(x) and w( p/6)=0 and
w( p/3)=0,x,w) ¸
w=
e
p
3
øxøcos(3шx)
10
м
e
p
6
øxøsin(3øx)
10
+
x ⋅
e x
10
det() MATH/Matrix menu
det( squareMatrix[ , tol] ) ⇒ expression
Returns the determinant of squareMatrix .
Optionally, any matrix element is treated as
zero if its absolute value is less than
tol . This
tolerance is used only if the matrix has
floating-point entries and does not contain
any symbolic variables that have not been
assigned a value. Otherwise,
tol is ignored.
• If you use ¥ ¸ or set the mode to
Exact/Approx=APPROXIMATE , computations
are done using floating-point arithmetic.
•
If tol is omitted or not used, the default
tolerance is calculated as:
5 E л 14 щ max(dim( squareMatrix ))
ù rowNorm( squareMatrix )
det([a,b;c,d]) ¸ aø d ì bø c
det([1,2;3,4]) ¸ ë 2
det(identity(3) ì xщ [1,л 2,3;
л 2,4,1;л 6,л 2,7]) ¸
л (98ш xт м 55ш xс + 12ш x ì 1)
[1 E 20,1;0,1]!mat1 [
1. E 20 1
0 1
]
det(mat1) ¸ 0
det(mat1,.1) ¸ 1. E 20
diag() MATH/Matrix menu
diag( list ) ⇒ matrix
diag( rowMatrix ) ⇒
matrix
diag( columnMatrix ) ⇒ matrix
Returns a matrix with the values in the
argument list or matrix in its main diagonal.
diag({2,4,6}) ¸ 


 2 0 0
0 4 0
0 0 6
diag( squareMatrix ) ⇒ rowMatrix
Returns a row matrix containing the
elements from the main diagonal of
squareMatrix .
squareMatrix must be square.
[4,6,8;1,2,3;5,7,9] ¸ 


 4 6 8
1 2 3
5 7 9
diag(ans(1)) ¸ [4 2 9]