Preface

A great discovery solves a great problem but there is a grain of discovery in the
solution of any problem. Your problem may be modest; but if it challenges your
curiosity and brings into play your inventive faculties, and if you solve it by your
own means, you may experience the tension and enjoy the triumph of discovery.
G E O R G E P O L Y A
The art of teaching, Mark Van Doren said, is the art of assisting discovery. I have tried to
write a book that assists students in discovering calculus—both for its practical power and
its surprising beauty. In this edition, as in the first six editions, I aim to convey to the student
a sense of the utility of calculus and develop technical competence, but I also strive
to give some appreciation for the intrinsic beauty of the subject. Newton undoubtedly
experienced a sense of triumph when he made his great discoveries. I want students to
share some of that excitement.
The emphasis is on understanding concepts. I think that nearly everybody agrees that
this should be the primary goal of calculus instruction. In fact, the impetus for the current
calculus reform movement came from the Tulane Conference in 1986, which formulated
as their first recommendation:
Focus on conceptual understanding.
I have tried to implement this goal through the Rule of Three: “Topics should be presented
geometrically, numerically, and algebraically.” Visualization, numerical and graphical experimentation,
and other approaches have changed how we teach conceptual reasoning in fundamental
ways. The Rule of Three has been expanded to become the Rule of Four by
emphasizing the verbal, or descriptive, point of view as well.
In writing the seventh edition my premise has been that it is possible to achieve conceptual
understanding and still retain the best traditions of traditional calculus. The book
contains elements of reform, but within the context of a traditional curriculum.
I have written several other calculus textbooks that might be preferable for some instructors.
Most of them also come in single variable and multivariable versions.
■ Calculus, Seventh Edition, Hybrid Version, is similar to the present textbook in
content and coverage except that all end-of-section exercises are available only in
Enhanced WebAssign. The printed text includes all end-of-chapter review material.
■ Calculus: Early Transcendentals, Seventh Edition, is similar to the present textbook
except that the exponential, logarithmic, and inverse trigonometric functions are covered
in the first semester.

Alternative Versions

xii PREFACE
■ Calculus: Early Transcendentals, Seventh Edition, Hybrid Version, is similar to Calculus:
Early Transcendentals, Seventh Edition, in content and coverage except that all
end-of-section exercises are available only in Enhanced WebAssign. The printed text
includes all end-of-chapter review material.
■ Essential Calculus is a much briefer book (800 pages), though it contains almost all
of the topics in Calculus, Seventh Edition. The relative brevity is achieved through
briefer exposition of some topics and putting some features on the website.
■ Essential Calculus: Early Transcendentals resembles Essential Calculus, but the
exponential, logarithmic, and inverse trigonometric functions are covered in Chapter 3.
■ Calculus: Concepts and Contexts, Fourth Edition, emphasizes conceptual understanding
even more strongly than this book. The coverage of topics is not encyclopedic
and the material on transcendental functions and on parametric equations is woven
throughout the book instead of being treated in separate chapters.
■ Calculus: Early Vectors introduces vectors and vector functions in the first semester
and integrates them throughout the book. It is suitable for students taking Engineering
and Physics courses concurrently with calculus.
■ Brief Applied Calculus is intended for students in business, the social sciences, and
the life sciences.
The changes have resulted from talking with my colleagues and students at the University
of Toronto and from reading journals, as well as suggestions from users and reviewers.
Here are some of the many improvements that I’ve incorporated into this edition:
■ Some material has been rewritten for greater clarity or for better motivation. See, for
instance, the introduction to maximum and minimum values on page 198, the introduction
to series on page 727, and the motivation for the cross product on page 832.
■ New examples have been added (see Example 4 on page 1045 for instance). And the
solutions to some of the existing examples have been amplified. A case in point: I
added details to the solution of Example 1.6.11 because when I taught Section 1.6
from the sixth edition I realized that students need more guidance when setting up
inequalities for the Squeeze Theorem.
■ Chapter 1, Functions and Limits, consists of most of the material from Chapters 1
and 2 of the sixth edition. The section on Graphing Calculators and Computers is
now Appendix G.
■ The art program has been revamped: New figures have been incorporated and a substantial
percentage of the existing figures have been redrawn.
■ The data in examples and exercises have been updated to be more timely.
■ Three new projects have been added: The Gini Index (page 351) explores how to
measure income distribution among inhabitants of a given country and is a nice application
of areas between curves. (I thank Klaus Volpert for suggesting this project.)
Families of Implicit Curves (page 163) investigates the changing shapes of implicitly
defined curves as parameters in a family are varied. Families of Polar Curves (page
688) exhibits the fascinating shapes of polar curves and how they evolve within a
family.

What’s New in the Seventh Edition?
PREFACE xiii
■ The section on the surface area of the graph of a function of two variables has been
restored as Section 15.6 for the convenience of instructors who like to teach it after
double integrals, though the full treatment of surface area remains in Chapter 16.
■ I continue to seek out examples of how calculus applies to so many aspects of the
real world. On page 933 you will see beautiful images of the earth’s magnetic field
strength and its second vertical derivative as calculated from Laplace’s equation. I
thank Roger Watson for bringing to my attention how this is used in geophysics and
mineral exploration.
■ More than 25% of the exercises are new. Here are some of my favorites: 2.2.13–14,
2.4.56, 2.5.67, 2.6.53–56, 2.7.22, 3.3.70, 3.4.43, 4.2.51–53, 5.4.30, 6.3.58, 11.2.49–50,
11.10.71–72, 12.1.44, 12.4.43–44, and Problems 4, 5, and 8 on pages 861–62.

Calculus (2nd Edition) Written by James Stewart

• A Preview of Calculus
• Functions and Models
• Limits and Derivatives
• Differentiation Rules
• Applications of Differentiation
• Integrals
• Applications of Integration
• Differential Equations
• Infinite Sequences and Series
• Vectors and the Geometry of Space
• Vector Functions
• Partial Derivatives
• Multiple Integrals
• Vector Calculus
• Appendixes
• REFERENCE PAGES

1. Beginning Photoshop Author Brad Shirakawa

2. Adobe Photoshop CS Tutorial Author Hong Kong Institute of Vocational Education

3. Photoshop Basics Quick Reference Guide Author Jeremy Hardin

4. Using the Photoshop Toolbox Author Higher Education Pearson

5. Shortcut Tables Author Martin Evening

6. Photoshop for Fun Author Radford University

7. Image Editing With Photoshop Author Heartland Community College

8. Layers Filters Colors and Projects Author Bangladesh Open University

9. Photoshop Express App Tutorial (Article) Author Jane Frederick

10. Photoshop Advanced Techniques (Artcle) Author Jesus Ramirez

11. Adobe Photoshop Elements 10 (Article) Author Utica Public Library

12. Introduction to Photoshop CC 2019 (Article) Author Digital Design Studios

13. Photoshop Tools and Panels (Article) Author The University of Utah

14. The Photoshop CS3 Toolbar (Article) Author EdShare University of Southampton

15. Saving PDF Files From Photoshop (Article) Author Publication Printers

16. How To Remove Or Replace a Background In Photoshop (Article) Author Ben Stockton

17. 3 Techniques to Remove Background in Photoshop (Article) Author SinaLite

18. Remove Background in Photoshop (Article) Author North Dakota State University

19. Creating Transparent Background in Photoshop (Article) Author Inside Scripps College

01.Microsoft Excel Manual Author University of Mary Washington

02.Excel Fundamentals Author-St. Georges University of London

03. Advanced spreadsheets – Microsoft Excel 2010 Author Mariza Maini

04. Essential Spreadsheets Book 1 Author University of York

05. Excel 2010 Advanced Author STL Training

06. Advanced Excel – Vlookup, Hlookup and Pivot Tables – Excel 2010 Author Liz Cooke

07. MS-Excel Lecture Notes Author Government Arts College Coimbatore

08. Microsoft Excel Advanced Author Towson University – Maryland’s University of Opportunities

09. Microsoft Excel Tips & Tricks Author Mynda Treacy

10. Excel Advanced Author Shasta County Office of Education

11. Formulas & Functions in Microsoft Excel Autor Theresa A Scott, MS

12. Microsoft Excel for Beginners Author Pandora Rose Cowart

13. Introduction to Excel Author Routledge – Publisher of Professional & Academic Books

14. Intro to Excel spreadsheets Author U.S. Environmental Protection Agency – US EPA

15. Excel Functions – Full List Author Western Sydney University

16. Creating Basic Excel Formulas Author Syracuse University – Syracuse.edu

17. Chapter 3 Logical Functions Author Watsonia Publishing

18. Advanced Formulas and Functions in Microsoft Excel (Article) Author UIS-Universidad Industrial de Santander

19. Excel-Introduction to Formulas (Article) Autor Shasta County Office of Education

20. Excel Cheat Sheet Basic Skills Author CustomGuide Microsoft Office Training – Excel Courses

21. Excel Formulas Author University of Detroit Mercy

What is Quantum Theory?
Quantum theory is the most successful set of ideas ever devised by human
beings. It explains the periodic chart of the elements and why chemical reactions
take place. It gives accurate predictions about the operation of lasers and
microchips, the stability of DNA and how alpha particles tunnel out of the
nucleus.

Since Don’t Make Me Think was first published in 2000, hundreds of thousands of Web designers and developers have relied on usability guru Steve Krug’s guide to help them understand the principles of intuitive navigation and information design. Witty, commonsensical, and eminently practical, it’s one of the best-loved and most recommended books on the subject.

Preface: About this edition
People come and go so quickly here!
—DOROTHY GALE (JUDY GARLAND) IN THE WIZARD OF OZ (1939)
I wrote the first edition of Don’t Make Me Think back in 2000.
By 2002, I began to get a few emails a year from readers asking (very
politely) if I’d thought about updating it. Not complaining; just trying to be
helpful. “A lot of the examples are out of date” was the usual comment.
My standard response was to point out that since I wrote it right around the
time the Internet bubble burst, many of the sites I used as examples had
already disappeared by the time it was published. But I didn’t think that made
the examples any less clear.
Finally, in 2006 I had a strong personal incentive to update it.1
But as I reread
it to see what I should change, I just kept thinking “This is all still true.” I
really couldn’t find much of anything that I thought should be changed.
1
Half of the royalties for the book were going to a company that no longer existed, and doing a
new edition meant a new contract—and twice the royalties—for me.
If it was a new edition, though, something had to be different. So I added
three chapters that I didn’t have time to finish back in 2000, hit the snooze
button, and happily pulled the covers back over my head for another seven
years.

Don’t Make Me Think!
SECOND EDITION
Steve Krug

Introduction
This is a book about instructing computers. Computers are about as common
as screwdrivers today, but they are quite a bit more complex, and making them
do what you want them to do isn’t always easy.
If the task you have for your computer is a common, well-understood one,
such as showing you your email or acting like a calculator, you can open the
appropriate application and get to work. But for unique or open-ended tasks,
there probably is no application.
That is where programming may come in. Programming is the act of con
structing a program—a set of precise instructions telling a computer what to do.
Because computers are dumb, pedantic beasts, programming is fundamentally
tedious and frustrating.
Fortunately, if you can get over that fact, and maybe even enjoy the rigor
of thinking in terms that dumb machines can deal with, programming can be
rewarding. It allows you to do things in seconds that would take forever by
hand. It is a way to make your computer tool do things that it couldn’t do
before. And it provides a wonderful exercise in abstract thinking.
Most programming is done with programming languages. A programming
language is an artificially constructed language used to instruct computers. It
is interesting that the most effective way we’ve found to communicate with a
computer borrows so heavily from the way we communicate with each other.
Like human languages, computer languages allow words and phrases to be
combined in new ways, making it possible to express ever new concepts.
At one point language-based interfaces, such as the BASIC and DOS prompts
of the 1980s and 1990s, were the main method of interacting with computers.
They have largely been replaced with visual interfaces, which are easier to learn
but offer less freedom. Computer languages are still there, if you know where
to look. One such language, JavaScript, is built into every modern web browser
and is thus available on almost every device.
This book will try to make you familiar enough with this language to do
useful and amusing things with it.

There are many more people who want to study programming other than aspiring computer scientists with a passing grade in advanced calculus. This guide appeals to your intelligence and ability to solve practical problems, while gently teaching the most recent revision of the programming language Python.

Introducing Python
So, you want to learn programming. Welcome to one of the great adventures of the twenty-first century.
Programming requires little in the way of specialized equipment; the software tools can all be
downloaded for free off the Internet, and it can be practiced in the safety and comfort of your own home,
without having to ask anyone’s permission. This chapter will ease you in gently by introducing you to the
software you will need to create your programs: a command-line interface, which allows you to use
Python in interactive mode, and a text editor for writing scripts—nothing more complicated than that. I
will also show you where to go to find help and documentation, so you can decode the sometimes
impenetrable jargon that seems to surround this, the geekiest of all technical disciplines. To begin with,
you will need to make sure that you have a decently recent version of Python installed on your machine
or follow the steps later in this chapter to install it (see “Choosing the Right Python Version” for a
definition of decently recent). This chapter explains how to make sure that you have everything set up
correctly and that you have suitable references at hand before you start your journey.
Python is an excellent language with which to learn programming. There are many reasons for this,
but the simple explanation is that it’s easy to read and fast to write; it doesn’t take long to come up with
working code that does something meaningful. Python has a very human-friendly syntax, which makes
writing elegant code easy. The basic language is fairly simple and therefore easy to remember, and then
it has an extensive library of predefined functions that you can use to facilitate most common computer
tasks. Writing effective applications in Python can be as simple as playing with conceptual building
blocks. It works really well for writing a little two-line application to perform some routine system
administration task or to provide interactive functions on a web page, but it has enough power and
flexibility to comfortably create much larger and more complex applications with graphic interfaces
indistinguishable from the programs you are used to running from your computer’s main menu. If you
follow the suggestions laid out in this book about writing self-explanatory code, in several months, even
years, you will be able to come back to your programs and see immediately what they were supposed to
do and what your original intentions were; this makes maintaining programs much simpler too.
OK, let’s make sure your system is ready for you to start running Python programs.

Illustrations by various artists: Cover by Wasif Hyder. Computer (introduction) and unicycle people (Chapter 21) by Max Xiantu. Sea of bits (Chapter 1) and weresquirrel (Chapter 4) by Margarita Martínez and José Menor.