HP 15c Collector's Edition User Manual

Section 11: Calculating With Complex Numbers 125
 Multiply by −1.
 If you don’t want to disturb the rest of the stack, press ” ´
} ” ´ }.
To find the negative of only one part of a complex number in the X-
register:
 Press ” to negate the real part only.
 Press ´ } ” ´ } to negate the imaginary part
only, forming the complex conjugate.
Clearing a Complex Number
Inevitably you will need to clear a complex number. You can clear only one
part at a time, but you can then write over both parts (since − and `
disable the stack).
Clearing the Real X-Register. Pressing − (or | `) with the
calculator in Complex mode clears only the number in the real X-register;
it does not clear the number in the imaginary X-register.
Example: Change 6 + 8i to 7 + 8i and subtract it from the previous entry.
(Use ´ } or ´ % to view the imaginary part in X.) Assume a,
b, c, and d represent parts of complex numbers.
Re Im Re Im Re Im Re Im
T
a b a b a b a b
Z
c d c d c d a b
Y 6 0 6 0 6 0
c d
X 6 8 0 8 7 8 −1 −8
Keys:
−
7 -
(or other
operation)
Since clearing disables the stack (as explained above), the next number
you enter will replace the cleared value. If you want to replace the real
part with zero, after clearing use v or any other function to
terminate digit entry (otherwise the next number you enter will write over
the zero); the imaginary part will remain unchanged. You can then
continue with any calculator function.

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.