HP 15c - Manual (Page 179)

Section 12: Calculating with Matrices 179
Keystroke(s) Results
O <
Designates matrix specified in X-register as result
matrix.
´ U
Row and column numbers in R
0
and R
1
are
automatically incremented each time O or l
{A through E, %} is pressed.
∕
Inverts matrix specified in X-register. Stores in result
matrix. Use ´ ∕
if User mode is on.
+, -
If matrix descriptors specified in both X- and Y-
registers, adds or subtracts corresponding elements of
matrices specified. If matrix descriptor specified in only
one of these registers, performs addition or subtraction
with all elements in specified matrix and scalar in other
register. Stores in result matrix.
*
If matrix descriptors specified in both X- and Y-
registers, calculates product of specified matrices (as
YX). If matrix specified in only one of these registers,
multiplies all elements in specified matrix by scalar in
other register. Stores in result matrix.
÷
If matrix descriptors specified in both X- and Y-
registers, multiplies inverse of matrix specified in X-
register with matrix specified in Y-register. If matrix
specified in only Y-register, divides all elements of
specified matrix by scalar in other register. If matrix
specified in only X-register, multiplies each element of
inverse of specified matrix by scalar in other register.
Stores in result matrix.
For Further Information
The HP-15C Advanced Functions Handbook presents more detailed and
technical aspects of the matrix functions in the HP-15C, including
applications. The topics include: least-squares calculations, solving
nonlinear equations, ill-conditioned and singular matrices, accuracy
considerations, iterative refinement, and creating the identity matrix.