Limit of a continuous angle
$begingroup$
Let $gamma :[0,1] to mathbb{R}^2$ be an injective continuous map. Consider point $P$ in $mathbb{R}^2$ outside of the curve $gamma$ and $A,B$ be the two ending points $gamma(0)$, $gamma(1)$ of the curve respectly. We fix point $M$ on the curve somewhere between $A$ and $B$. Now point $C$ on the curve moves continuously from $A$ to $B$ crossing $M$.
What can we say about both left and right limits of $lim_{C to M} angle PCM$ ? (the angle is signed with respect to clockwork orienration).
geometry limits
$endgroup$
add a comment |
$begingroup$
Let $gamma :[0,1] to mathbb{R}^2$ be an injective continuous map. Consider point $P$ in $mathbb{R}^2$ outside of the curve $gamma$ and $A,B$ be the two ending points $gamma(0)$, $gamma(1)$ of the curve respectly. We fix point $M$ on the curve somewhere between $A$ and $B$. Now point $C$ on the curve moves continuously from $A$ to $B$ crossing $M$.
What can we say about both left and right limits of $lim_{C to M} angle PCM$ ? (the angle is signed with respect to clockwork orienration).
geometry limits
$endgroup$
$begingroup$
I would guess they represent the angle at which the line segment PM crosses the image of $gamma$.
$endgroup$
– Stan Tendijck
Jan 27 at 0:28
add a comment |
$begingroup$
Let $gamma :[0,1] to mathbb{R}^2$ be an injective continuous map. Consider point $P$ in $mathbb{R}^2$ outside of the curve $gamma$ and $A,B$ be the two ending points $gamma(0)$, $gamma(1)$ of the curve respectly. We fix point $M$ on the curve somewhere between $A$ and $B$. Now point $C$ on the curve moves continuously from $A$ to $B$ crossing $M$.
What can we say about both left and right limits of $lim_{C to M} angle PCM$ ? (the angle is signed with respect to clockwork orienration).
geometry limits
$endgroup$
Let $gamma :[0,1] to mathbb{R}^2$ be an injective continuous map. Consider point $P$ in $mathbb{R}^2$ outside of the curve $gamma$ and $A,B$ be the two ending points $gamma(0)$, $gamma(1)$ of the curve respectly. We fix point $M$ on the curve somewhere between $A$ and $B$. Now point $C$ on the curve moves continuously from $A$ to $B$ crossing $M$.
What can we say about both left and right limits of $lim_{C to M} angle PCM$ ? (the angle is signed with respect to clockwork orienration).
geometry limits
geometry limits
edited Jan 27 at 0:11
Bungo
13.7k22148
13.7k22148
asked Jan 27 at 0:09
MasMMasM
11611
11611
$begingroup$
I would guess they represent the angle at which the line segment PM crosses the image of $gamma$.
$endgroup$
– Stan Tendijck
Jan 27 at 0:28
add a comment |
$begingroup$
I would guess they represent the angle at which the line segment PM crosses the image of $gamma$.
$endgroup$
– Stan Tendijck
Jan 27 at 0:28
$begingroup$
I would guess they represent the angle at which the line segment PM crosses the image of $gamma$.
$endgroup$
– Stan Tendijck
Jan 27 at 0:28
$begingroup$
I would guess they represent the angle at which the line segment PM crosses the image of $gamma$.
$endgroup$
– Stan Tendijck
Jan 27 at 0:28
add a comment |
1 Answer
1
active
oldest
votes
$begingroup$
Line $CM$, as $Cto M$, tends to the line tangent at $M$ to the curve (provided that tangent exists, i.e. if $gamma$ is differentiable). Hence $angle PCM$ tends to the angle between line $PM$ and the tangent at $M$. Of course left and right limit give the two (different) angles formed by such lines.
$endgroup$
add a comment |
Your Answer
StackExchange.ifUsing("editor", function () {
return StackExchange.using("mathjaxEditing", function () {
StackExchange.MarkdownEditor.creationCallbacks.add(function (editor, postfix) {
StackExchange.mathjaxEditing.prepareWmdForMathJax(editor, postfix, [["$", "$"], ["\\(","\\)"]]);
});
});
}, "mathjax-editing");
StackExchange.ready(function() {
var channelOptions = {
tags: "".split(" "),
id: "69"
};
initTagRenderer("".split(" "), "".split(" "), channelOptions);
StackExchange.using("externalEditor", function() {
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled) {
StackExchange.using("snippets", function() {
createEditor();
});
}
else {
createEditor();
}
});
function createEditor() {
StackExchange.prepareEditor({
heartbeatType: 'answer',
autoActivateHeartbeat: false,
convertImagesToLinks: true,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: 10,
bindNavPrevention: true,
postfix: "",
imageUploader: {
brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
allowUrls: true
},
noCode: true, onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
});
}
});
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f3088951%2flimit-of-a-continuous-angle%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
1 Answer
1
active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
$begingroup$
Line $CM$, as $Cto M$, tends to the line tangent at $M$ to the curve (provided that tangent exists, i.e. if $gamma$ is differentiable). Hence $angle PCM$ tends to the angle between line $PM$ and the tangent at $M$. Of course left and right limit give the two (different) angles formed by such lines.
$endgroup$
add a comment |
$begingroup$
Line $CM$, as $Cto M$, tends to the line tangent at $M$ to the curve (provided that tangent exists, i.e. if $gamma$ is differentiable). Hence $angle PCM$ tends to the angle between line $PM$ and the tangent at $M$. Of course left and right limit give the two (different) angles formed by such lines.
$endgroup$
add a comment |
$begingroup$
Line $CM$, as $Cto M$, tends to the line tangent at $M$ to the curve (provided that tangent exists, i.e. if $gamma$ is differentiable). Hence $angle PCM$ tends to the angle between line $PM$ and the tangent at $M$. Of course left and right limit give the two (different) angles formed by such lines.
$endgroup$
Line $CM$, as $Cto M$, tends to the line tangent at $M$ to the curve (provided that tangent exists, i.e. if $gamma$ is differentiable). Hence $angle PCM$ tends to the angle between line $PM$ and the tangent at $M$. Of course left and right limit give the two (different) angles formed by such lines.
edited Jan 28 at 11:38
answered Jan 27 at 9:24
AretinoAretino
25.5k21445
25.5k21445
add a comment |
add a comment |
Thanks for contributing an answer to Mathematics Stack Exchange!
- Please be sure to answer the question. Provide details and share your research!
But avoid …
- Asking for help, clarification, or responding to other answers.
- Making statements based on opinion; back them up with references or personal experience.
Use MathJax to format equations. MathJax reference.
To learn more, see our tips on writing great answers.
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f3088951%2flimit-of-a-continuous-angle%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
$begingroup$
I would guess they represent the angle at which the line segment PM crosses the image of $gamma$.
$endgroup$
– Stan Tendijck
Jan 27 at 0:28