Post any errors that you find in the printed version of the course text below. To aid in avoiding any repeats, please do it as follows:
In the subject put something like
"page xx, line yy"
then in the body of the post put the error. If it's near the bottom of the page put "page xx, line -yy," meaning the error is yy lines up from the bottom. Count equations as lines as well.
Points:
typos = 1 homework point
substantive errors = 10 homework points
really major errors = 10's of homework points
Obviously what constitutes the distinction between these three types of errors is a matter of degree. I'll use my best judgment to allocate points fairly.
Only the first person to post an error will receive any credit, so try not to repeat any others that have already been posted.
page 1, line -3 states that there are 2^5=32 possible classifications based on the five categories listed. However, I do not believe that this is actually correct because some possibilities are restricted. For example, we do not classify nonlinear equations as homogeneous or inhomogeneous. Therefore, there are actually less than 32 possible categorizations (20, I think). The 32 categorizations are also mentioned on the first line of page 2.
page 5, line -13 is the definition of the partial derivative. The first t after the limit is missing the subscript 1.
(this is on the second page of the preface)
the end of the line reads "...methods (section and 1.9)."
there is an extra 'and' added or a section number missing.
page 14: Under Theorem 1.7.1, the second bracket should be closed instead of open.
page 15: In the last paragraph in section 1.7, I think 'propery' should be changed to 'properly' and 'exitence' to 'existence.'
page i, line 2 "and students other disciplines" should read "and students of other disciplines"
line 4 "This material that is traditionally" should read "This is material that is traditionally" or "This material is traditionally"
line 7 There should be a comma after the word "Specifically"
page ii, line 12 "would simply to bring" should read "would be simply to bring"
This is just a formatting mistake... There should be a space inbetween the listing of each chapter-section number and the title of each section, but often the space is missing (i.e. "12.10The first five terms..." to "12.10 The first five terms...").
Oops, I forgot to put the label above so I re-posted it.
p. xvii, xix, xx
This is just a formatting mistake... There should be a space inbetween the listing of each chapter-section number and the title of each section, but often the space is missing (i.e. "12.10The first five terms..." to "12.10 The first five terms...").
I'm not sure how to fix this exactly, but I think you need to eliminate either "will always be orthogonal to r and h about the center of the hoop" or "will always be orthogonal to the plane of the hoop."
For Problem 1.1 in the 1.10 Exercises, neither #7,10,12 nor 13 should have time differentials for intial conditions as time is not an independent variable.
The sentence is incomplete:
"This text will only consider nth order ordinary differential equation may be written in the form..."
should be: "This text will...equations that can be written in the form..."
This line shows a Matlab command format. TSPAN is skipped in the subsequent definitions of each part of the command. Even though it is fairly obvious what TSPAN might be, it seems strange that it is omitted.
You wrote "...the Boit number, , which is defined as..."
I think you meant to have a variable between the commas, otherwise you just have too many commas.
I'm not completely sure how to fix this, but its just an inconsistency. I think that x_p(t)=c_0e(t) should probably be defined as x_p(t)=c_1e(t) because when you substitute it into the equation, you use c_1 instead of c_0.
The same thing happens for equation 2.3. The specific heat of the material is said to have units of J/kg*K (equivalent to J*K/kg) when it should have units of J/(kg*K).
In example 2.3.19, a - is dropped from the integral of sin(t), this error is carried through to the end of the example.
On page 43, 14 lines from the bottom, the phrase "the change in plasma glucose concentrations due to uptake by, say in, skeletal muscle" needs to be rewritten
the statement of example 2.2.4 cites cocaine as an illicit example of a drug, just seems out of place and there is no previous reference to cocaine, example 2.2.3 is about alcohol and might have been about cocaine at one point but other that that the statement just feels very out of place and unnecessary
In Step 4 in the algorithm for Euler's method for a given delta t, there should be a delta t on the f(x(t0+(n-1)deltat),t0+(n-1)deltat) term: f(x(t0+(n-1)deltat),t0+(n-1)deltat)DELTAt.
On lines 13 and 14, you defined
x1^=sin (natural frequency*t) and x2^=cos(natural frequency*t), but then on line 27 when you substituted them in you did the opposite. I think based on the convention used for c1^ and c2^ it should be x1^=cos(natural frequency*t) on line 13 and x2^=sin(natural frequency*t) on line 14.
In problem 3.11, there is an extra Zeta symbol in the middle term on the left-hand side of the equation. I believe there only needs to be one in that term.
The equation on the bottom of page 73 currently reads x(t) = c1e^λ1t + c2e^ λ2t. Because this section is describing repeated roots, however, the two λ values (λ1 and λ2) are the same and therefore do not need to be distinguished from each other. This means that the subscripts of 1 and 2 can be eliminated from the λ variables. In the first part of Theorem 3.3.6 (giving the x(t) functions) this convention is used and the λ variables are written without subscript.
"Now consider the problem of a coupled by a spring to a vibrating base."
should read:
"Now consider the problem of a spring coupled to a vibrating base."
or something along those lines.
p. 74, line 25
The sentence "While not necessary to simply find..." seems to lacks a verb in this clause ... perhaps it should be "While it is not necessary to simply find..."
On page 95 line 9, I think the equation for x(0) should be positive rather than negative in order to make the homogeneous solutions zero so that the complete solution is the particular solution.
On page 97 line 7, in equation (4.9) I think the inhomogeneous term should include the natural frequency rather than omega.
page 101 line 5: "is" should be changed to "are"
page 109 line 18: "good" should be added so it reads "is probably a good idea"
"...the method of undetermined coefficients is probably most expedient solution method." needs to have a "the" inserted so it says "...the method of undetermined coefficients is probably THE most expedient solution method."
I'm not sure if maybe "a" or "the" should be added to the sentence "This is in contrast with multiple degree of freedom system..." so it becomes "This is contrast with a multiple degree of freedom system..." or "This is in contrast with the multiple degree of freedom system...".
pg 115 line 11: "to obtain an better approximation" should be changed to "obtain a better approximation"
pg 119 line -2: "more an more" should be changed to "more and more"
pg 120 lines 18-21 I think this sentence should be broken into two. Perhaps add a period after "independent variable." Then start the next sentence with "Attempts to increase the accuracy..."
p 127 line -12: "initial condition" changed to "initial conditions"
p 129 line -10: "Figure 5.3" should be changed to "Figure 5.6"
p 130 line 3: "where lambda is an positive integer" should be changed to "a positive integer"
This seems like something so obvious I think it might have been done on purpose, but are you aware that there is no section 5.4?
The title reads, "5.4 Series Solutions about a Singular Point," and then the book promptly skips to the title "5.5. A Collection of Famous Series Solutions." There is no text at all between Sections 5.4 and 5.5. Is there something missing, or was that done temporarily on purpose for now?
line 15: "...covering what has been traditionally been the subject..." One too many beens
line 23: "...label of "engineering analysis" many homework problems..." Should be a comma after analysis
where it reads "there may be, in fact, up to n different solutions to the form x = e^..."
it should be x = ce^...
without the c, you don't know what to vary to get the different forms
It says that the force is always directed in the opposite direction of the velocity of the mass
In actuality, the force is always directed in the opposite direction of the POSITION/DISPLACMENT of the mass
For confirmation, see figure 4.9:
at the point t = 1, the displacement is negative, the velocity is the slope of the x(t) graph, and has a positive value, and the force has a positive value
"As has already been stated, the dependence of f on x and t is specified, but the dependence of x on t"...you should probably add "has not been specified"
last equation, if it is supposed to be a direct simplification of the above equation, is incorrect.
the part above the division line should read:
x(2.5) - 2x(2.0) + x(1.5)
instead of
x(2.5) - 2x(1.5) + x(1.5)
On page 360 Line 10, the first line of Equation 12.2, I believe the first equal sign should be multiplication
On page 369, Figure 12.7, I think the label on the vertical axis is incorrect (it is the same as the one on Figure 12.6, which was a different example)
On page 383 Line 12 and line 16, after the summation symbol there is an infinity that should be above the summation symbol
On page 387 Line 5, the sentence ends with "in Figure 12.19 through ??", which should be through Figure 12.22
On page 393 Line 25, starting with "which has a general solution Y(y)= ..., both exponents of e have 'pi' rather than the symbol for pi
On page 396, very last line, I believe that the X(x) should be d2*sin(sqrt())...the sin has been omitted
On page 397 line 9, the index for the Y(y) should be 'm', not 'n'
On page 401 the second line, first equation: the last term should be a partial du_ss not du_tr
On page 403 line 14 "We need to relate" not "related"
You say you're substituting into Equation 12.3.1, but that's not an equation number. I think you meant to say the first equation in section 12.3.1 which doesn't have a number.
p. 383
when solving for the coefficient cn in the step where you have multiplied by the integral from 0 to L and sin(m*pi*x/L) you drop cn from the equation and just have the integral of sin squared equals the integral of sin time f(x)
p. 401
when you express the boundary conditions in the middle of the page you are missing equals signs at the end of three of them so it looks like you are multiplying. u(Lx,y,t)=utr(Lx,y,t)+uss(Lx,y,t)0 and the next two.
in the last line before example 14.1.5, it states that t = 0,2pi,3pi,4pi...
then, in example 14.1.5, t is defined as t = 2m*pi.
Then, both claim to refer to the same figure, 14.5.
If m is an integer, which it usually is, then the initial definition for t should not include the 3pi term.
reads "and noting that since x1 and x2 the terms in the parentheses..."
should read "and noting that since x1 and x2 are the terms in the parentheses.."
"try to make the term in the left set of parentheses zero"
From looking at the work, I believe that the term which becomes zero is actually the term in the RIGHT parentheses