HP 39g Graphing Calculator - Manual (Page 180)

Matrix arithmetic
You can use the arithmetic functions (+, x, / ) with matrix
arguments. Division left-multiplies by the inverse of the
divisor. You can enter the matrices themselves or enter the
names of stored matrix variables. The matrices can be real or
complex.
For the next four examples, store [[1,2],[3,4]] into Ml and
[[5,6],[7,8]] into M2.
Example 1. Create the first matrix.
|SHiFT|M/tTOX EHH S3
s
1
1 ENTER) 2 ¡ENTER)
3 ¡ENTER) 4 1 enter !
Create the second
matrix.
¡ENTER) 6 ¡ENTER)
¡ENTER |8 ¡ENTER)
|SHiFT|M/tre/x [▼ ] i ; h ,B,I
Mi 1
2
1 1 2
i H
M2 1 2
1 5 6
d B
3. Add the matrices that you created
I HOME 11 ALPHA |M1 |T]
I alpha |M2 [ enter
I
^FUNCT ■
m+ri2
[[6,8],C10,12]]
To multiply and
divide by a scalar
For division by a scalar, enter the matrix first, then the
operator, then the scalar. For multiplication, the order of the
operands does not matter. The matrix and the scalar can be
real or complex. For example, to divide the result of the
previous example by
2
, use the following key presses:
[T] 2 I ente Y]
M1+M2
[[6,8],[10,12]]
Rnsx2
[[3,4],[5,6]]
12-6 Matrices