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First published 1998 (print)
Second edition published 2004 (print)
Third edition published 2008 (print)
Fourth edition published 2015 (print and electronic)
Fifth edition published 2019 (print and electronic)
©Pearson Education Limited 1998, 2004, 2008 (print)
©Pearson Education Limited 2015, 2019 (print and electronic)
The rights of Anthony Croft and Robert Davison to be identified as authors of this work have been asserted by them in accordance with the Copyright, Designs and Patents Act 1988.
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ISBN: 978-1-292-25364-0 (print) 978-1-292-25370-1 (eText) 978-1-292-25369-5 (ePub)
British Library Cataloguing-in-Publication Data
A catalogue record for the print edition is available from the British Library Library of Congress Cataloging-in-Publication Data
A catalog record for the print edition is available from the Library of Congress
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Print edition typeset in 10/12 limes by Pearson CSC Print edition printed in Slovakia by Neografia
NOTE THAT ANY PAGE CROSS REFERENCES REFER TO THE PRINT EDITION
To Kate and Harvey (AC)
To Kathy (RD)
Block 4 Trigonometrical functions and their graphs
Block 5 Trigonometrical identities
Block 6 Trigonometrical equations
Block 7 Engineering waves
End of chapter exercises
10 Further trigonometry
Block 1 Pythagoras's theorem and the solution of right-angled triangles
Block 2 Solving triangles using the sine rule
Block 3 Solving triangles using the cosine rule
Block 4 Surveying
Block 5 Resolution and resultant of forces
End of chapter exercises
11 Complex numbers
Block 1
Block 2
Block3
Block4
Block 5
Block 6
Arithmetic of complex numbers
The Argand diagram and polar form of a complex number
The exponential form of a complex number
De Moivre's theorem
Solving equations and finding roots of complex numbers
Phasors
End of chapter exercises
12 Matrices and determinants
Block 1
Block 2
Block3
Block4
Block 5
Introduction to matrices
Multiplication of matrices
Determinants
The inverse of a matrix
Computer graphics
End of chapter exercises
13 Using matrices and determinants to
solve equations
Block 1
Block 2
Block3
Block4
Block 5
Block 6 Cramer's rule
Using the inverse matrix to solve simultaneous equations
Gaussian elimination
Eigenvalues and eigenvectors
Iterative techniques
Electrical networks
End of chapter exercises
14 Vectors
Block 1
Block 2
Basic concepts of vectors
Cartesian components of vectors
19 Sequences and series
Block 1
Block 2
Block3
Block4
Sequences and series
Sums of whole numbers, their squares and cubes
Pascal's triangle and the binomial theorem
Taylor, Maclaurin and other series
End of chapter exercises
20 Differential equations
Block 1 Basic concepts of differential equations 980
Block 2 Separation of variables 995
Block 3 Solving first-order linear equations using an integrating factor 1003
Block 4 Computational approaches to differential equations 1011
Block 5 Second-order linear constant-coefficient equations I 1021
Block 6 Second-order linear constant-coefficient equations II 1034
End of chapter exercises 1046
21 Functions of more than one variable and partial differentiation
Block 1
Block 2 Functions of two independent variables, and their graphs
Partial differentiation
Block 3 Higher-order derivatives
Block 4 Partial differential equations
Block 5 Stationary values of a function of two variables
End of chapter exercises
22 The Laplace transform
Block 1
Block 2
Block3 The Laplace transform The inverse Laplace transform Solving differential equations using the Laplace transform
End of chapter exercises
23 Statistics and probability
Block 1
Block 2
Block3
Block4
Block 5
Block 6
Block7
Blocks
Block 9 Data Data averages
Variation of data
Elementary probability
Laws of probability
Probability distributions
The binomial distribution
The Poisson distribution
The normal distribution
End of chapter exercises
24 An introduction to Fourier series and the Fourier transform
Block 1 Periodic waveforms and their Fourier representation
Block 2 Introducing the Fourier transform End of chapter exercises
Typical examination papers
Appendix 1: SI units and prefixes
Index
Companion Website
For open-access student resources specifically written to complement this textbook and support your learning, please visit www.pearsoned.eo.uk/croft
Lecturer Resources
For password-protected on line resources tailored to support the use of this textbook in teaching, please visit www.pearsoned.eo.uk/croft
We are grateful to the following for permission to reproduce copyright material: The screenshots in this book are Copyright © Waterloo Maple Inc., xxi and The MathWorks, Inc., xxii and reprinted with permission.
Audience
This book has been written to serve the mathematical needs of students engaged in a first course in engineering or technology at degree level. Students of a very wide range of these programmes will find that the book contains the mathematical methods they will meet in a first-year course in most UK universities. So the book will satisfy the needs of students of aeronautical, automotive, chemical, civil, electronic and electrical, systems, mechanical, manufacturing, and production engineering, and other technological fields. Care has been taken to include illustrative examples from these disciplines where appropriate.
Aims
There are two main aims of this book.
Firstly, we wish to provide a readable, accessible and student-friendly introduction to mathematics for engineers and technologists at degree level. Great care has been taken with explanations of difficult concepts, and wherever possible statements are made in everyday language, as well as symbolically. It is the use of symbolic notation that seems to cause many students problems, and we hope that we have gone a long way to alleviate such problems.
Secondly, we wish to develop in the reader the confidence and competence to handle mathematical methods relevant to engineering and technology through an interactive approach to learning. You will find that the book encourages you to take an active part in the learning process - this is an essential ingredient in the learning of mathematics.
of this book
The book has been divided into 24 chapters. Each chapter is subdivided into a unit called a block. A block is intended to be a self-contained unit of study. Each block has a brief introduction to the material in it, followed by explanations, examples and applications. Important results and key points are highlighted. Many of the examples require you to participate in the problem-solving process, so you will need to have pens or pencils, scrap paper and a scientific calculator to hand. We say more about this aspect below. Solutions to these examples are all given alongside.
Each block also contains a number of practice exercises, and the solutions to these are placed immediately afterwards. This avoids the need for searching at the back of the book for solutions. A further set of exercises appears at the end of each block. At the end of each chapter you will find end of chapter exercises, which are designed to consolidate and draw together techniques from all the blocks within the chapter.
Some sections contain computer or calculator exercises. These are denoted by the computer icon. It is not essential that these are attempted, but those of you with access to graphical calculators or computer software can see how these modem technologies can be used to speed up long and complicated calculations.
Learning mathematics
In mathematics almost all early building blocks are required in advanced work. New ideas are usually built upon existing ones. This means that, if some early topics are not adequately mastered, difficulties are almost certain to arise later on. For example, if you have not mastered the arithmetic of fractions, then you will find some aspects of algebra confusing. Without a firm grasp of algebra you will not be able to perform the techniques of calculus, and so on. It is therefore essential to try to master the full range of topics in your mathematics course and to remedy deficiencies in your prior knowledge.
Learning mathematics requires you to participate actively in the learning process. This means that in order to get a sound understanding of any mathematical topic it is essential that you actually perform the calculations yourself. You cannot learn mathematics by being a spectator. You must use your brain to solve the problem, and you must write out the solution. These are essential parts of the learning process. It is not sufficient to watch someone else solve a similar problem, or to read a solution in a book, although these things of course can help. The test of real understanding and skill is whether or not you can do the necessary work on your own.
How to use this book
This book contains hundreds of fully worked examples. When studying such an example, read it through carefully and ensure you understand each stage of the calculation.
A central feature of the book is the use of interactive examples that require the reader to participate actively in the learning process. These examples are indicated
by the pencil icon. Make sure you have to hand scrap paper, pens or pencils and a calculator. Interactive examples contain 'empty boxes' and 'completed boxes'. An empty box indicates that a calculation needs to be performed by you. The corresponding completed box on the right of the page contains the calculation you should have performed. When working through an interactive example, cover up the completed boxes, perform a calculation when prompted by an empty box, and then compare your work with that contained in the completed box. Continue in this way through the entire example. Interactive examples provide some help and structure while also allowing you to test your understanding.
Sets of exercises are provided regularly throughout most blocks. Try these exercises, always remembering to check your answers with those provided. Practice enhances understanding, reinforces the techniques, and aids memory. Carrying out a large number of exercises allows you to experience a greater variety of problems, thus building your expertise and developing confidence.
Content
The content of the book reflects that taught to first-year engineering and technology students in the majority of UK universities. However, particular care has been taken to develop algebraic skills from first principles and to give students plenty of opportunity to practise using these. It is our firm belief, based on recent experience of teaching engineering undergraduates, that many will benefit from this material because they have had insufficient opportunity in their previous mathematical education to develop such skills fully. Inevitably the choice of contents is a compromise, but the topics covered were chosen after wide consultation coupled with many years of teaching experience. Given the constraint of space we believe our choice is optimal.
Use of modern IT aids
One of the main developments in the teaching of engineering mathematics in recent years has been the widespread availability of sophisticated computer software and its adoption by many educational institutions. Once a firm foundation of techniques has been built, we would encourage its use, and so we have made general references at several points in the text. In addition, in some blocks we focus specifically on two common packages (Matlab and Maple), and these are introduced in the 'Using mathematical software packages' section on page xx. Many features available in software packages can also be found in graphical calculators.
On pages xxiii-xxiv we provide a reference table of Maple and Matlab commands that are particularly useful for exploring and developing further the topics in this book.
Additions for the fifth edition
We have been delighted with the positive response to Mathematics for Engineers since it was first published in 1998. In writing this fifth edition we have been guided and helped by the numerous comments from both staff and students. For these comments we express our thanks.
This fifth edition has been enhanced by the addition of numerous examples from even wider fields of engineering. Applicability lies at the heart of engineering mathematics. We believe these additional examples serve to reinforce the crucial role that mathematics plays in engineering. We hope that you agree.
Following useful suggestions from reviewers we have added new sections to cover the equation of a circle, locus of a point in the complex plane and solution of partial differential equations. We have enhanced and integrated the use of software in the solution of engineering problems.
We hope the book supports you in your learning and wish you every success.
Anthony Croft and Robert Davison May2018
One of the main developments influencing the learning and teaching of engineering mathematics in recent years has been the widespread availability of sophisticated computer software and its adoption by many educational institutions.
As engineering students, you will meet a range of software in your studies. It is also highly likely that you will have access to specialist mathematical software. Two software packages that are particularly useful for engineering mathematics, and which are referred to on occasions throughout this book, are Matlab and Maple. There are others, and you should enquire about the packages that have been made available for your use. A number of these packages come with specialist tools for subjects such as control theory and signal processing, so you will find them useful in other subjects that you study.
Common features of all these packages include:
• the facility to plot two- and three-dimensional graphs;
• the facility to perform calculations with symbols (e.g. a 2 , x + y, as opposed to just numbers) including the solution of equations.
In addition, some packages allow you to write computer programs of your own that build upon existing functionality, and enable the experienced user to create powerful tools for the solution of engineering problems
The facility to work with symbols, as opposed to just numbers, means that these packages are often referred to as computer algebra systems or symbolic processors. You will be able to enter mathematical expressions, such as (x + 2)(x - 3) or 2 t6 , and subject them to all of the common mathematical operations: t +2t+l simplification, factorisation, differentiation, integration, and much more. You will be able to perform calculations with vectors and matrices. With experience you will find that lengthy, laborious work can be performed at the click of a button.
Figure 1
A screenshot from Maple showing the package being used to define the function f(x) = :l- + 3x -2 and plot its graph.
The particular form in which a mathematical problem is entered - that is, the syntax - varies from package to package. Raising to a power is usually performed using the symbol 11.. Some packages are menu driven, meaning that you can often select symbols from a menu or toolbar. At various places in the text we have provided examples of this for illustrative purposes. This textbook is not intended to be a manual for any of the packages described. For thorough details you will need to refer to the manual provided with your software or its on-line help.
At first sight you might be tempted to think that the availability of such a package removes the need for you to become fluent in algebraic manipulation and other mathematical techniques. We believe that the converse of this is true. These packages are sophisticated, professional tools and as such require the user to have a good understanding of the functions they perform, and particularly their limitations. Furthermore, the results provided by the packages can be presented in a variety of forms (as you will see later in the book), and only with a thorough understanding of the mathematics will you be able to appreciate different, yet correct, equivalent forms, and distinguish these from incorrect output.
Figure 1 shows a screenshot from Maple in which we have defined the function f(x) = x2 + 3x -2 and plotted part of its graph. Note that Maple requires the following particular syntax to define the function: f: = x---+ x 2 + 3x - 2. The quantity x2 is input as x11.2.
Finally, Figure 2 shows a screenshot from the package Matlab. Here the package is being used to obtain a three-dimensional plot of the surface z = sin(x2 + y2) as described in Chapter 21. Observe the requirement of Matlab to input x2 as x • 11.2.
Figure2
A screenshot from Matlab showing the package being used to plot a threedimensional graph.
Where appropriate we would encourage you to explore the use of packages such as these. Through them you will find that whole new areas of engineering mathematics become accessible to you, and you will develop skills that will help you to solve engineering problems that you meet in other areas of study and in the workplace.
Useful mathematical software commands used throughout the book
The following commands are indicative only and should be read in conjuction with the software's on-line help and the examples found later in the book.
Purpose
Test whether an integer, n, is prime
Produce a prime factorisation of an integer, n
Plot graph of y =j{x)
Finding partial fractions expansion
Complex numbers
Find roots of a polynomial
Defining matrices
Eigenvalues and eigenvectors
Vectors: scalar and vector products
Maple example
isprime(n)
ifactor(n)
plot(xA3,x=-3 3,y=-20 20);
convert(x/(xA2+3*x+2), parfrac); use I (1+3*I)/(2-I)
solve(sA3+sA2+s+l=O)
A:= Matrix([[l,2,3], [4,5,6], [7,8,9]])
Eigenvalues(A) Eigenvectors(A) with(LinearAlgebra);
a:= Vector[row] ( [1,-2,3]);
b:= Vector[row] ( [2,-1,1]); DotProduct(a,b); CrossProduct(a,b);
Matlab example isprime(n)
factor(n)
x=-3:0.1:3; y=x.A3; plot(x,y);
n = [1]; d=[132]; [r,p,k] = residue(n,d)
use i or j (1+3*j)/(2-j)
roots ( [ 1 1 1 1] )
A = [1 2 3; 4 5 6; 7 8 9]
[V, D] = eig(A)
a= [1 -2 3] b=[2 -1 1]
dot(a,b) cross(a,b)
Purpose
First and higher derivatives
Indefinite and definite integration
Differential equations with or without conditions
Sums of series
Taylor series
Maple example
f:=t-> tA2*sin(3*t);
D(f) (t); or diff(f(t) ,t);
D(D(f))(t); or diff(f(t),t,t);
int(x*cos(x)A2,x)
int(l/t,t=l. .2)
dsolve(diff(y(x),x) - x*y(x)=O); dsolve({diff(y(x),x) - x*y(x)=0,y(0)=3})
sum(l/k,k=l .. 10); taylor(sqrt(x),x=4,4);
3dplots
plot3d(xA2+yA2,x=-2 .. 2,y=-2 .. 2);
Matlab example
syms f(t)
f(t) = tA2*sin(3*t) y = dif f ( f ( t) l Z = dif f ( f ( t ) 2 )
syms x t int(x*cos(x)A2,x) int(l/t,1,2)
dsolve('Dy-x*y=O', 'x') dsolve ( 'Dy-x*y=O', ' Y ( 0) =3 ' X ' )
sym k symsum(l/k,k,l,10)
taylor (sqrt (x), 'ExpansionPoint',4, 'Order', 4)
Laplace transform
Fourier transform
with(inttrans): f:=t->tA2; laplace(f(t),t,s); with(inttrans); f:=t->Heaviside(t)*exp(-t); fourier(f(t),t,w);
[x,y]=meshgrid(-2:0.1:2, -2:0.1:2); Z = X.A2+y.A2; mesh(z); syms t s f=tA2 laplace(f,t,s)
syms t w f = heaviside(t)*exp(t) fourier(f,t,w)
