154 Section 12: Calculating with Matrices
Keystrokes
Display
-
C
2
3
Calculates
B - A
and stores
values in redimensioned result
matrix
C
.
The result is
8
4
3
2
1
0
C
Matrix Multiplication
With matrix description in both the X- and Y-registers, you can calculate
three different matrix products. The table below shows the results of the
three functions for a matrix
X
specified in the X-register and a matrix
Y
specified in the Y-register. The matrix
X
-1
is the inverse of
X
, and the
matrix
Y
T
is the transpose of
Y
.
Pressing
Calculates*
*
YX
´
>
5
Y
T
X
÷
X
-1
Y
* Result is stored in result matrix. For
÷
, the
result matrix can be
Y
but not
X
. For the others,
the result matrix must be other than
X
or
Y
.
Note:
When you use the
÷
function to evaluate the expression
A
-1
B
, you must enter the matrix descriptors in the order
B
,
A
rather
than in the order that they appear in the expression.
*
The value stored in each element of the result matrix is determined
according to the usual rules of matrix multiplication.
For
>
5
,
the matrix specified in the Y-register isn't changed by this
operation, even though its transpose is used. The result is identical to that
obtained using
>
4 (transpose) and
*
.
*
This is the same order you would use if you were entering
b
and
a
for evaluating a
-1
b =
b/a
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 ...
