HP 39gs Master Manual page 211

Another method is to store the result into a third matrix and then to view it through the Edit screen of the
. This is shown below.
MATRIX Catalog
Probably the most common functions that you will use are
worked examples are included which use them. There are also a number of further worked examples
involving matrices in the section at the back of the book.
Solving a system of equations
Eg. 1 Solve the system of equations:
Solution: The system of equations can be
represented as the system of
matrices:
and this system can then be algebraically
rearranged to:
where the inverse matrix is...
which gives a final answer of
The method for doing this on the calculator is as follows...
Step 1. Enter the
MATRIX Catalogue
matrices if desirable.
Matrix is
M3
created left and
edited right.
INVERSE, DET
+ 3 − = −6
⎧ 2
x y z
⎪
− 3 + = 12
⎨ x
y z
⎪ 3 − + 4
z =
⎩
x y 13
⎡
2
⎢
1
⎢
⎢ ⎣
3
⎡ ⎤
x
⎢ ⎥
y
⎢ ⎥
⎢ ⎥
⎣ ⎦
z
⎡ 2
⎢
⎢ 1
⎢ 3
⎣
⎡ ⎤ ⎡ ⎤
x 2
y ⎢ ⎥ ⎢ ⎥
= −3
⎢ ⎥ ⎢ ⎥
z ⎢ ⎥ ⎢ ⎥
⎣ ⎦ ⎣ ⎦
1
. Use to erase all
SHIFT CLEAR
211
and (transpose), so some
TRN
1 − −6
⎤ ⎡ ⎤ ⎡ ⎤
3 x
⎥ ⎢ ⎥ ⎢ ⎥
− = 12
3 1 y
⎥ ⎢ ⎥ ⎢ ⎥
⎥ ⎢ ⎥ ⎢ ⎥
−
⎦ ⎣ ⎦ ⎣ ⎦
1 4 z 13
−1
1 − −6
⎡ ⎤ ⎡ ⎤
2 3
⎢ 1 ⎥ ⎢ ⎥
= −
3 1 ⎥ ⎢ 12
⎢ ⎥
⎢ 4 ⎥ ⎢ ⎥
−
⎣ ⎦ ⎣ ⎦
3 1 13
−1
−
1 ⎤
3
1 ⎥ ⎥
−
3
4 ⎥ ⎦
−
1