HP 15c Collector's Edition User Manual

Section 12: Calculating with Matrices 147
Example: Recall the element in row 2, column 1 of matrix A from the
previous example. Use the stack registers.
Keystrokes Display
2 v 1
1
Enters row number into
Y-register and column
number into X-register.
l | A
4.0000
Value of a
21
.
Storing a Number in All Elements of a Matrix
To store a number in all elements of a matrix, simply key that number into
the display, then press O > followed by the letter key
specifying the matrix.
Matrix Operations
In many ways, matrix operations are like numeric calculations. Numeric
calculations require you to specify the numbers to be used; often you
define a register for storing the result. Similarly, matrix calculations
require you to specify one or two matrices that you want to use. A matrix
descriptor is used to specify a particular matrix. For many calculations,
you also must specify a matrix for storing the result. This is the result
matrix.
Because matrix operations usually require many individual calculations,
the calculator flashes the running display during most matrix
operations.
Matrix Descriptors
Earlier in this section you saw that when you press l >
followed by a letter key specifying a matrix, the name of the matrix
appears at the left of the display and the number of rows followed by the
number of columns appears at the right. The matrix name is called the
descriptor of the matrix. Matrix descriptors can be moved among the
stack and data storage registers just like a number—that is, using O,
l, v, etc. Whenever a matrix descriptor is displayed in the X-
register, the current dimensions of that matrix are shown with it.
You use matrix descriptors to indicate which matrices are used in each
matrix operation. The matrix operations discussed in the rest of this

HP 15c Collector's Edition Specifications

General

Model	HP 15c Collector's Edition
Category	Calculator
Type	Scientific
Power Source	Battery
Manufacturer	HP
Display	LCD
Functions	complex numbers, matrix operations

Summary

Introduction

This Handbook

Outlines the structure of the manual, detailing its parts and how to use it for learning.

The HP Community

Discusses user groups and websites for HP calculator enthusiasts and information sharing.

Part I: HP 15c Fundamentals

Section 1: Getting Started

Covers basic operations like powering on, keyboard layout, and primary/alternate functions.

Section 2: Numeric Functions

Explains essential numeric operations including logs, trig, powers, and conversions.

Section 3: The Automatic Memory Stack, LAST X, and Data Storage

Details the RPN stack, LAST X register, and data storage operations.

Part II: HP 15c Programming

Section 6: Programming Basics

Introduces core programming concepts: creating, loading, running programs, and memory.

Section 8: Program Branching and Controls

Covers controlling program flow using branching, loops, and conditional tests.

Part III: HP 15c Advanced Functions

Section 11: Calculating With Complex Numbers

Covers entering, manipulating, and performing calculations with complex numbers.

Section 12: Calculating With Matrices

Explains matrix operations, including dimensioning, element access, and calculations.

Section 13: Finding the Roots of an Equation

Details using the SOLVE function for numerical root finding and equation solving.

Section 14: Numerical Integration

Explains how to perform numerical integration using the ∫f(x)dx key and subroutines.

Appendix A: Error Conditions

Error 8: No Root

Explains the error when the SOLVE function cannot find a root.

Error 0: Improper Mathematics Operation

Lists and explains errors related to mathematical operations and illegal arguments.

Appendix D: A Detailed Look at SOLVE

How SOLVE Works

Explains the numerical technique and logic behind the SOLVE algorithm.

Finding Several Roots

Discusses methods for finding multiple roots of an equation using the SOLVE function.