HP HP-15C

172 Section 12: Calculating with Matrices
1.
Store the elements of A in memory, in the form either of A
P
or of
A
C
.
2.
Recall the descriptor of the matrix representing A into the display.
3.
If the elements of A were entered in the form A
C
, press ´ p
to transform A
C
into A
P
.
4.
Press ´> 2 to transform A
P
into Ã.
5.
Press O< to designate the matrix representing A as the
result matrix.
6.
Press ∕ to calculate (Ã)
-1
.
7.
Redimension A to have half the number of rows as indicated in the
display of its descriptor after the preceding step.
8.
Store the elements of B in memory, in the form either of B
P
or
of B
C
.
9.
Recall the descriptor of the matrix representing A into the display.
10.
Recall the descriptor of the matrix representing B into the display.
11.
If the elements of B were entered in the form B
C
, press ´p to
transform B
C
into B
P
.
12.
Press ´> 2 to transform B
P
into 

13.
Designate the result matrix; it must not be the same matrix as either
of the other two.
14.
Press *.
15.
Press ´> 4 to transpose the result matrix.
16.
Press ´> 2.
17.
Redimension the result matrix to have half the number of rows as
indicated in the display of its descriptor after the preceding step.
18.
Press l< to recall the descriptor of the result matrix.
19.
Press ´> 4 to calculate X
P
.
20.
If you want the solution in the form X
C
, press |c