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''ì2w'/x+(9+2/x^2)w=
xùe^(x) and w(p/6)=0 and
w(p/3)=0,x,w) ¸
w=
e
p
3øxøcos(3øx)
10
ì
e
p
6øxøsin(3øx)
10 +
x⋅ex
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:
5Eë14 ùmax(dim(squareMatrix))
ùrowNorm(squareMatrix)
det([a,b;c,d]) ¸aød ìbøc
det([1,2;3,4]) ¸ë2
det(identity(3) ìxù[1,ë2,3;
ë2,4,
1
;ë6,ë2,7
])
¸
ë
(
98øx
ò
ì55øx
ñ
+
1
2øx ì
1)
[1E20,1;0,1]!mat1 [1.E20 1
0 1]
d
et
(
mat
1)
¸
0
d
et
(
mat
1
,.
1)
¸1
.E20
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]