Section 12: Calculating With Matrices - HP -15C Owner's Handbook Manual

Calculating With Matrices
The HP-15C enables you to perform matrix calculations, giving you the
capability to handle advanced problems with ease. The calculator can work
with up to five matrices, which are named A through E since they are
accessed using the corresponding A through E keys. The HP-15C lets
you specify the size of each matrix, store and recall the values of matrix
elements, and perform matrix operations – for matrices with real or
complex elements. (A summary of matrix functions is listed at the end of
this section.)
A common application of matrix calculations is solving a system of linear
equations. For example, consider the equations
for which you must determine the values of x
These equations can be expressed in matrix form as AX = B, where

A
The following keystrokes show how easily you can solve this matrix
problem using your HP-15C. (The matrix operations used in this example
are explained in detail later in this section.)
First, dimension the two known matrices, A and B, and enter the values of
their elements, from left to right along each row from the first row to the
last. Also, designate matrix C as the matrix that you will use to store the
result of your matrix calculation (C = X).
Section 12
3.8x + 7.2x
1
1.3x - 0.9x
1
 
3.8 7.2
    , X

1.3 0.9
= 16.5
2
= -22.1
2
and x
1 2
 
x
1
 
 
, and
B
 
x
2
138
.
 
16.5
.
   

22.1