HP 48g Graphing Calculator - Manual (Page 175)

Calculating with Matrix Elements
To add or subtract two matrices:
1. Enter the two matrices onto the stack in the same order as you
would to add or subtract real numbers. They must have the same
dimensions.
2. Press (2 to add or Q to subtract. The single resulting matrix
has elements that are the sum or difference of the corresponding
elements in the original argument matrices.
To multiply or diwide a matrix by a scalar:
1. Enter the matrix onto the stack.
2. Enter the scalar (a real or complex number).
3. Press Q or Q- Each element of the resulting matrix is the product
or quotient of the scalar and the corresponding element in the
original argument matrix.
To change the sign of each element in a matrix:
1. Enter the matrix onto the stack.
2. Press (Sto change the sign of each element, in the matrix.
To find the matrix product
( A B )
of two matrices:
1. Enter the two matrices onto the stack. Be careful about the entry
order because matrix multiplication is not commutative. Enter
matrix A first and matrix B second. Remember also that the
number of columns in A must equal the number of rows in B.
2. Press Q. The result will be a matrix with the same number of
rows as A and the same number of columns as B.
14
To multiply a matrix and vector:
1. Enter the matrix onto the stack.
2. Enter the vector. The number of elements in the vector must equal
the number of columns in the matrix.
3. Press Q. The result will be a vector with as many elements as the
number of rows in the original matrix.
Matrices and Linear Algebra 14-11