Section 12: Calculating with Matrices 167
8. Press
*
to calculate
X
P
= (
YX
)
P
. The values of these matrix
elements are placed in the result matrix, and the descriptor of
the result matrix is placed in the X-register.
9. If you want the product in the form (
YX
)
C
, press
|c
Note that you don't transform
X
P
into
.
You can derive the complex elements of the matrix product
YX
by recalling
the elements of (
XY
)
P
or (
YX
)
C
and combining them according to the
conventions described earlier.
Example:
Calculate the product
ZZ
-1
, where
Z
is the complex matrix given
in the preceding example.
Since elements representing both matrices are already stored (
in
A
and
(
Z
-1
)
P
in
B
), skip steps 1, 3, 4, and 6.
Keystrokes
Display
l>A
A
4
4
Displays descriptor of matrix
A
.
l>B
b
4
2
Displays descriptor of matrix
B
.
´<C
b
4
2
Designates
C
as result matrix.
*
C
4
2
Calculates
(
Z
-1
)
P
= (
ZZ
-1
)
P
.
´U
C
4
2
Activates User mode.
lC
C
1,1
Matrix
C
, row 1, column 1.
(Displayed momentarily while
last key held down.)
1.0000
Value of
c
11
.
lC
–2.8500 –10
Value of
c
12
.
lC
–4.0000 –11
Value of
c
21
.
lC
1.0000
Value of
c
22
.
lC
1.0000 –11
Value of
c
31
.
lC
3.8000 –10
Value of
c
32
.
lC
1.0000 –11
Value of
c
41
.
lC
–1.0500 –10
Value of c
42
.
´U
–1.0500 –10
Deactivates User mode.
Summary of Contents for HP-15C
Page 1: ...HP 15C Owner s Handbook HP Part Number 00015 90001 Edition 2 4 Sep 2011 ...
Page 17: ...Part l HP 15C Fundamentals ...
Page 64: ......
Page 65: ...Part ll HP 15C Programming ...
Page 118: ...118 ...
