Math for Real Life: Teaching Practical Uses for Algebra, Geometry and Trigonometry

213 Pages·2017·1.84 MB·English

by  Jim Libby

Math for Real Life
This page intentionally left blank
Math for Real Life
Teaching Practical Uses
for Algebra, Geometry
and Trigonometry
J L
iM ibby
McFarland & Company, Inc., Publishers
Jefferson, North Carolina
LibRaRyofCongRessCataLoguing-in-PubLiCationData
names: Libby, Jim, 1955–
title: Math for real life : teaching practical uses for algebra,
geometry and trigonometry / Jim Libby.
Description: Jefferson, north Carolina : Mcfarland & Company, inc., 2017. |
includes bibliographical references and index.
identifiers: LCCn 2016052898 | isbn 9781476667492
(softcover : acid free paper)
♾
subjects: LCsH: Mathematics—study and teaching. |
algebra—study and teaching. | geometry—study and teaching. |
trigonometry—study and teaching.
Classification: LCC Qa135.6 .L54 2017 | DDC 510.71—dc23
LC record available at https://lccn.loc.gov/2016052898
bRitisHLibRaRyCataLoguingDataaReavaiLabLe
ISBN (print) 978-1-4766-6749-2
ISBN (ebook) 978-1-4766-2675-8
© 2017 Jim Libby. all rights reserved
No part of this book may be reproduced or transmitted in any form
or by any means, electronic or mechanical, including photocopying
or recording, or by any information storage and retrieval system,
without permission in writing from the publisher.
front cover images © 2017 istock
Printed in the united states of america
McFarland & Company, Inc., Publishers
Box 611, Jefferson, North Carolina 28640
www.mcfarlandpub.com
for Donna
This page intentionally left blank
t C
abLe of ontents
Preface 1
Introduction 5
i. algebra i 7
ii. geometry 53
iii. algebra ii 90
iv. advanced Math 129
v. trigonometry 165
Afterword 187
Chapter Notes 189
Bibliography 195
Index 201
vii
This page intentionally left blank
P
RefaCe
Many people react much as the mother on the television show The Mid-
dle did when her son got a D on a math paper: “Math is very important in
life. you use math in everything… . oh even I can’t say it like i believe it.”
What are students thinking when they say, “Where are we ever going to
use this?” yes, it could be a cynical ploy and not really a legitimate ques-
tion. Maybe it’s an attempt to divert the teacher’s attention away from the
math at hand. Maybe it’s just a chance to stir things up so it gets a little inter-
esting.
yet, even if there are ulterior motives, most students really do wonder
what that answer is. for each student who is daring enough to ask it, there
are plenty of others who are thinking it. this question doesn’t seem to come
up in english classes—or in science, or government, or band, or health class.
all of us tend to shy away from parts of our lives that are difficult and point-
less. there isn’t much to be done about the difficulty of mathematics, but
mathematics is far from pointless. an argument can be made that mathe-
matics is the most useful development in the history of mankind. yet for
many potential mathematicians sitting in high school classes, ironically, it
seems without purpose.
in spite of that, it can be difficult for secondary math teachers to come
up with answers to the question “Where are we ever going to use this?” there
are several reasons for this difficulty.
• Much of the math that is taught in high school needs additional knowl-
edge to be applied. there are many applications available to the indi-
vidual that understands calculus, although very few high school
students will have had calculus. or, perhaps a greater knowledge of
the area of the application itself is needed. a math teacher seeking to
understand the formula for electrical resistance in a series would prob-
ably need to spend a lot more time understanding the electronics than
the mathematics.
1