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Apply fixes for errata from Thomas Mahoney
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jirilebl committed May 9, 2019
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17 changes: 9 additions & 8 deletions ch-contfunc.tex
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Expand Up @@ -2397,7 +2397,7 @@ \subsection{Limits at infinity}
\begin{equation*}
\abs{f(x) - L} < \epsilon
\end{equation*}
whenever $x \geq M$, then we say $f(x)$
whenever $x \in S$ and $x \geq M$, then we say $f(x)$
\emph{converges}\index{converges!function} to $L$
as $x$ goes to $\infty$. We call $L$ the \emph{limit}
and write
Expand All @@ -2414,7 +2414,7 @@ \subsection{Limits at infinity}
\begin{equation*}
\abs{f(x) - L} < \epsilon
\end{equation*}
whenever $x \leq M$, then we say $f(x)$ \emph{converges} to $L$
whenever $x \in S$ and $x \leq M$, then we say $f(x)$ \emph{converges} to $L$
as $x$ goes to $-\infty$. We call $L$ the \emph{limit} and write
\begin{equation*}
\lim_{x \to -\infty} f(x) := L .
Expand Down Expand Up @@ -2481,7 +2481,7 @@ \subsection{Limits at infinity}
\begin{equation*}
\lim_{n\to\infty} f(x_n) = L
\end{equation*}
for all sequences $\{ x_n \}$ such that $\lim\limits_{n\to\infty} x_n = \infty$.
for all sequences $\{ x_n \}$ in $S$ such that $\lim\limits_{n\to\infty} x_n = \infty$.
\end{lemma}

The lemma holds for the limit as $x \to -\infty$.
Expand All @@ -2500,8 +2500,8 @@ \subsection{Limits at infinity}
We prove the converse by contrapositive. Suppose $f(x)$ does
not go to $L$ as $x \to \infty$.
This means that there exists an $\epsilon > 0$,
such that for every $M \in \N$, there exists an $x \in S$, $x \geq M$, let
us call it $x_M$, such that $\abs{f(x_M)-L} \geq \epsilon$.
such that for every $n \in \N$, there exists an $x \in S$, $x \geq n$, let
us call it $x_n$, such that $\abs{f(x_n)-L} \geq \epsilon$.
Consider the sequence $\{ x_n \}$. Clearly
$\{ f(x_n) \}$ does not converge to $L$. It remains to note
that $\lim\, x_n = \infty$, because $x_n \geq n$ for all $n$.
Expand Down Expand Up @@ -2805,7 +2805,7 @@ \subsection{Continuity of monotone functions}
we have $\abs{f(x)-a} < \epsilon$.
\end{proof}

Suppose $f \colon S \to \R$, $c \in S$, and
Suppose $f \colon S \to \R$ is increasing, $c \in S$, and
that both one-sided limits exist.
Since $f(x) \leq f(c) \leq f(y)$
whenever $x < c < y$, taking the limits we obtain
Expand Down Expand Up @@ -3084,11 +3084,12 @@ \subsection{Exercises}
{\ }
\begin{enumerate}[a)]
\item
Let $S \subset \R$ be any subset. If $f \colon S \to \R$ is increasing,
Let $S \subset \R$ be any subset. If $f \colon S \to \R$ is increasing and
bounded,
then show that there exists an increasing $F \colon \R \to \R$
such that $f(x) = F(x)$ for all $x \in S$.
\item
Find an example of a strictly increasing $f \colon S \to \R$ such that
Find an example of a strictly increasing bounded $f \colon S \to \R$ such that
an increasing $F$ as above is never strictly increasing.
\end{enumerate}
\end{exercise}
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4 changes: 2 additions & 2 deletions ch-der.tex
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Expand Up @@ -917,9 +917,9 @@ \subsection{Continuity of derivatives and the intermediate value theorem}
$\frac{g(x)-g(b)}{x-b} < 0$ or that $g(x) > g(b)$, thus
$g$ cannot possibly have a maximum at $b$.
Therefore, $c \in (a,b)$,
and \hyperref[thm:rolle]{Rolle's theorem} applies: As $g$ attains a maximum
and \lemmaref{relminmax:lemma} applies: As $g$ attains a maximum
at $c$ we find $g'(c) = 0$
and $f'(c) = y$.
and so $f'(c) = y$.

Similarly, if $f'(a) > y > f'(b)$, consider $g(x) := f(x)- yx$.
\end{proof}
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18 changes: 9 additions & 9 deletions ch-riemann.tex
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Expand Up @@ -202,7 +202,7 @@ \subsection{Partitions and lower and upper integrals}
$k_0 < k_1 < \cdots < k_n$ such that $x_j = \widetilde{x}_{k_j}$ for
$j=0,1,2,\ldots,n$.

Let $\Delta \widetilde{x}_p = \widetilde{x}_{p-1} - \widetilde{x}_p$.
Let $\Delta \widetilde{x}_p = \widetilde{x}_p - \widetilde{x}_{p-1}$.
See \figureref{fig:refinement}.
We get
\begin{equation*}
Expand Down Expand Up @@ -2448,9 +2448,9 @@ \section{Improper integrals}
requires the optional \sectionref{sec:limitatinf})}

Often it is necessary to integrate over the
entire real line, or a infinite interval of the form $[a,\infty)$ or
$(\infty,b]$. Also, we may wish to integrate unbounded functions
defined on a finite interval $(a,b)$.
entire real line, or a unbounded interval of the form $[a,\infty)$ or
$(-\infty,b]$. Also, we may wish to integrate unbounded functions
defined on a open bounded interval $(a,b)$.
Such functions are not Riemann integrable, but we may want to write down
the integral anyway in the spirit of \lemmaref{lemma:boundedimpriemann}.
These integrals are called \emph{\myindex{improper integrals}},
Expand Down Expand Up @@ -2521,8 +2521,7 @@ \section{Improper integrals}
-
\frac{1^{-p+1}}{-p+1}
=
-
\frac{1}{(p-1)b^{p-1}}
\frac{-1}{(p-1)b^{p-1}}
+
\frac{1}{p-1} .
\end{equation*}
Expand Down Expand Up @@ -2799,7 +2798,7 @@ \section{Improper integrals}
if the limits exist.

Suppose $f \colon \R \to \R$ is a function such that
$f$ is Riemann integrable on all finite intervals $[a,b]$. Then
$f$ is Riemann integrable on all bounded intervals $[a,b]$. Then
we define
\begin{equation*}
\int_{-\infty}^\infty f := \lim_{c \to -\infty} \, \lim_{d \to \infty} \, \int_c^d f ,
Expand Down Expand Up @@ -2835,7 +2834,8 @@ \section{Improper integrals}
exist. Let us prove this fact only for the infinite limits.

\begin{prop}
If $f \colon \R \to \R$ is a function integrable on every interval.
If $f \colon \R \to \R$ is a function integrable on every bounded interval
$[a,b]$.
Then
\begin{equation*}
\lim_{a \to -\infty} \, \lim_{b \to \infty} \, \int_a^b f
Expand Down Expand Up @@ -2986,7 +2986,7 @@ \section{Improper integrals}
\operatorname{sinc}(x) =
\begin{cases}
\frac{\sin(x)}{x} & \text{if $x \not= 0$} , \\
0 & \text{if $x = 0$} .
1 & \text{if $x = 0$} .
\end{cases}
\end{equation*}
\begin{myfigureht}
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9 changes: 5 additions & 4 deletions ch-seq-ser.tex
Original file line number Diff line number Diff line change
Expand Up @@ -2637,7 +2637,7 @@ \section{Cauchy sequences}

Define $a := \limsup \, x_n$ and
$b := \liminf \, x_n$.
By \propref{seqconvsubseqconv:prop}, there exist subsequences
By \thmref{subseqlimsupinf:thm}, there exist subsequences
$\{ x_{n_i} \}$ and
$\{ x_{m_i} \}$, such that
\begin{equation*}
Expand Down Expand Up @@ -3214,7 +3214,7 @@ \subsection{Absolute convergence}
\end{proof}

If $\sum x_n$ converges absolutely, the limits of
$\sum x_n$ and $\sum \abs{x_n}$ are different. Computing one
$\sum x_n$ and $\sum \abs{x_n}$ may be different. Computing one
does not help us compute the other. However the computation above leads to
a useful inequality for absolutely convergent series,
a series version of the triangle inequality,
Expand All @@ -3241,7 +3241,7 @@ \subsection{Absolute convergence}
\sum_{n=1}^\infty \frac{1}{n}
\end{equation*}
diverges. Therefore,
$\sum \frac{{(-1)}^n}{n}$ is a conditionally convergent subsequence.
$\sum \frac{{(-1)}^n}{n}$ is a conditionally convergent series.

\subsection{Comparison test and the \texorpdfstring{$p$}{p}-series}

Expand Down Expand Up @@ -3464,7 +3464,8 @@ \subsection{Ratio test}
\end{prop}

\begin{proof}
From \lemmaref{seq:ratiotest} we note that if $L > 1$, then $x_n$
If $L > 1$, then
\lemmaref{seq:ratiotest} says that the sequence $\{ x_n \}$
diverges. Since it is a necessary condition for the convergence of series
that the terms go to zero, we know that $\sum x_n$ must diverge.

Expand Down
Binary file modified figures/invcontfigA.pdf
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4 changes: 2 additions & 2 deletions figures/invcontfigA.xp
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Expand Up @@ -17,8 +17,8 @@ int main()
line(P(0,1),P(1,2));

dot_size(3);
dot(P(0,0));
circ(P(0,1));
circ(P(0,0));
dot(P(0,1));

tikz_format();
end();
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Binary file modified figures/invcontfigB.pdf
Binary file not shown.
4 changes: 2 additions & 2 deletions figures/invcontfigB.xp
Original file line number Diff line number Diff line change
Expand Up @@ -17,8 +17,8 @@ int main()
line(P(1,0),P(2,1));

dot_size(3);
dot(P(0,0));
circ(P(1,0));
circ(P(0,0));
dot(P(1,0));

tikz_format();
end();
Expand Down

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