A problem on path connectedness of unit ball in R*RExtending a continuous function on the unit sphere to the...

What is Tony Stark injecting into himself in Iron Man 3?

New invention compresses matter to produce energy? or other items? (Short Story)

“I had a flat in the centre of town, but I didn’t like living there, so …”

Was it really inappropriate to write a pull request for the company I interviewed with?

Does the in-code argument passing conventions used on PDP-11's have a name?

Did Amazon pay $0 in taxes last year?

How spaceships determine each other's mass in space?

What is the purpose of a disclaimer like "this is not legal advice"?

Has a sovereign Communist government ever run, and conceded loss, on a fair election?

How does a sound wave propagate?

Why is there an extra space when I type "ls" on the Desktop?

Naming Characters after Friends/Family

Iron deposits mined from under the city

Dukha vs legitimate need

Why aren't there more gauls like Obelix?

What is better: yes / no radio, or simple checkbox?

Questions of the type "What do you think other people would think?"

Can a Mimic (container form) actually hold loot?

Create chunks from an array

Is there a way to find out the age of climbing ropes?

Is there a math expression equivalent to the conditional ternary operator?

Should I use HTTPS on a domain that will only be used for redirection?

School performs periodic password audits. Is my password compromised?

What can I do if someone tampers with my SSH public key?



A problem on path connectedness of unit ball in R*R


Extending a continuous function on the unit sphere to the unit ballConvexity implies the equivalence of order and subspace topologiesPath connectedness is a topological invariant?Questions on the counterexample for “connectedness doesn't imply path-connectedness”Compactness of the closed unit ball in the weak* topology: the Banach–Alaoglu theoremExample of Connected but Not-Path Connected SetShow that $T$(contains segments) is path connectedPath connectednessContinuity and path-connectednessLocal connectedness and path-connectedness of a square $Itimes I$.













0












$begingroup$


Actually, I am having a problem over the fact that as $f:[0,1]rightarrowmathbb{R}^{2}$ , $f(t)= (1-t)x + ty$ is continuous, $x,yinmathbb{R}^{2}$, then $f([0,1])$ is connected . Then as unit ball in $mathbb{R}^{2}$ is an ordered set in the order topology, by IVP of $f$ any point between $x=(0,1)$ and $y=(1,0)$ must have a pre-image in $[0,1]$ , but by the dictionary order topology, $(0,1)< z=(1/2,5/8) < (1,0)$ , but $z$ has no pre-image under $f$, but $z$ lies in the unit ball . Why ???
I want a clear explanation over this dubiousness .










share|cite|improve this question











$endgroup$












  • $begingroup$
    What is RR? Do you mean $mathbb{R}^2$? The unit ball is path connected, but you have to take paths $on the unit ball$. Think of the intersection of the ball with the plane that contains x, y, and the origin. The intersection is a great circle. The arc of the circle connecting x and y is a path.
    $endgroup$
    – Joel Pereira
    Mar 3 at 16:05










  • $begingroup$
    Yes Joel, I mean R*R, my confusion lies in the fact that when the points of the unit ball are written on a line, then for f(0)=(0,1) and f(1)=(1,0) , then by dictionary order (1/2,5/8) lies in between f(0) and f(1), and it also lies on the unit ball , then by IVP of f, it must have a pre-image in [0,1], where is that ?????
    $endgroup$
    – RABI KUMAR CHAKRABORTY
    Mar 3 at 18:16


















0












$begingroup$


Actually, I am having a problem over the fact that as $f:[0,1]rightarrowmathbb{R}^{2}$ , $f(t)= (1-t)x + ty$ is continuous, $x,yinmathbb{R}^{2}$, then $f([0,1])$ is connected . Then as unit ball in $mathbb{R}^{2}$ is an ordered set in the order topology, by IVP of $f$ any point between $x=(0,1)$ and $y=(1,0)$ must have a pre-image in $[0,1]$ , but by the dictionary order topology, $(0,1)< z=(1/2,5/8) < (1,0)$ , but $z$ has no pre-image under $f$, but $z$ lies in the unit ball . Why ???
I want a clear explanation over this dubiousness .










share|cite|improve this question











$endgroup$












  • $begingroup$
    What is RR? Do you mean $mathbb{R}^2$? The unit ball is path connected, but you have to take paths $on the unit ball$. Think of the intersection of the ball with the plane that contains x, y, and the origin. The intersection is a great circle. The arc of the circle connecting x and y is a path.
    $endgroup$
    – Joel Pereira
    Mar 3 at 16:05










  • $begingroup$
    Yes Joel, I mean R*R, my confusion lies in the fact that when the points of the unit ball are written on a line, then for f(0)=(0,1) and f(1)=(1,0) , then by dictionary order (1/2,5/8) lies in between f(0) and f(1), and it also lies on the unit ball , then by IVP of f, it must have a pre-image in [0,1], where is that ?????
    $endgroup$
    – RABI KUMAR CHAKRABORTY
    Mar 3 at 18:16
















0












0








0





$begingroup$


Actually, I am having a problem over the fact that as $f:[0,1]rightarrowmathbb{R}^{2}$ , $f(t)= (1-t)x + ty$ is continuous, $x,yinmathbb{R}^{2}$, then $f([0,1])$ is connected . Then as unit ball in $mathbb{R}^{2}$ is an ordered set in the order topology, by IVP of $f$ any point between $x=(0,1)$ and $y=(1,0)$ must have a pre-image in $[0,1]$ , but by the dictionary order topology, $(0,1)< z=(1/2,5/8) < (1,0)$ , but $z$ has no pre-image under $f$, but $z$ lies in the unit ball . Why ???
I want a clear explanation over this dubiousness .










share|cite|improve this question











$endgroup$




Actually, I am having a problem over the fact that as $f:[0,1]rightarrowmathbb{R}^{2}$ , $f(t)= (1-t)x + ty$ is continuous, $x,yinmathbb{R}^{2}$, then $f([0,1])$ is connected . Then as unit ball in $mathbb{R}^{2}$ is an ordered set in the order topology, by IVP of $f$ any point between $x=(0,1)$ and $y=(1,0)$ must have a pre-image in $[0,1]$ , but by the dictionary order topology, $(0,1)< z=(1/2,5/8) < (1,0)$ , but $z$ has no pre-image under $f$, but $z$ lies in the unit ball . Why ???
I want a clear explanation over this dubiousness .







general-topology connectedness path-connected






share|cite|improve this question















share|cite|improve this question













share|cite|improve this question




share|cite|improve this question








edited 17 hours ago









Robert Thingum

8931317




8931317










asked Mar 3 at 15:48









RABI KUMAR CHAKRABORTYRABI KUMAR CHAKRABORTY

565




565












  • $begingroup$
    What is RR? Do you mean $mathbb{R}^2$? The unit ball is path connected, but you have to take paths $on the unit ball$. Think of the intersection of the ball with the plane that contains x, y, and the origin. The intersection is a great circle. The arc of the circle connecting x and y is a path.
    $endgroup$
    – Joel Pereira
    Mar 3 at 16:05










  • $begingroup$
    Yes Joel, I mean R*R, my confusion lies in the fact that when the points of the unit ball are written on a line, then for f(0)=(0,1) and f(1)=(1,0) , then by dictionary order (1/2,5/8) lies in between f(0) and f(1), and it also lies on the unit ball , then by IVP of f, it must have a pre-image in [0,1], where is that ?????
    $endgroup$
    – RABI KUMAR CHAKRABORTY
    Mar 3 at 18:16




















  • $begingroup$
    What is RR? Do you mean $mathbb{R}^2$? The unit ball is path connected, but you have to take paths $on the unit ball$. Think of the intersection of the ball with the plane that contains x, y, and the origin. The intersection is a great circle. The arc of the circle connecting x and y is a path.
    $endgroup$
    – Joel Pereira
    Mar 3 at 16:05










  • $begingroup$
    Yes Joel, I mean R*R, my confusion lies in the fact that when the points of the unit ball are written on a line, then for f(0)=(0,1) and f(1)=(1,0) , then by dictionary order (1/2,5/8) lies in between f(0) and f(1), and it also lies on the unit ball , then by IVP of f, it must have a pre-image in [0,1], where is that ?????
    $endgroup$
    – RABI KUMAR CHAKRABORTY
    Mar 3 at 18:16


















$begingroup$
What is RR? Do you mean $mathbb{R}^2$? The unit ball is path connected, but you have to take paths $on the unit ball$. Think of the intersection of the ball with the plane that contains x, y, and the origin. The intersection is a great circle. The arc of the circle connecting x and y is a path.
$endgroup$
– Joel Pereira
Mar 3 at 16:05




$begingroup$
What is RR? Do you mean $mathbb{R}^2$? The unit ball is path connected, but you have to take paths $on the unit ball$. Think of the intersection of the ball with the plane that contains x, y, and the origin. The intersection is a great circle. The arc of the circle connecting x and y is a path.
$endgroup$
– Joel Pereira
Mar 3 at 16:05












$begingroup$
Yes Joel, I mean R*R, my confusion lies in the fact that when the points of the unit ball are written on a line, then for f(0)=(0,1) and f(1)=(1,0) , then by dictionary order (1/2,5/8) lies in between f(0) and f(1), and it also lies on the unit ball , then by IVP of f, it must have a pre-image in [0,1], where is that ?????
$endgroup$
– RABI KUMAR CHAKRABORTY
Mar 3 at 18:16






$begingroup$
Yes Joel, I mean R*R, my confusion lies in the fact that when the points of the unit ball are written on a line, then for f(0)=(0,1) and f(1)=(1,0) , then by dictionary order (1/2,5/8) lies in between f(0) and f(1), and it also lies on the unit ball , then by IVP of f, it must have a pre-image in [0,1], where is that ?????
$endgroup$
– RABI KUMAR CHAKRABORTY
Mar 3 at 18:16












0






active

oldest

votes











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
});


}
});














draft saved

draft discarded


















StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f3133642%2fa-problem-on-path-connectedness-of-unit-ball-in-rr%23new-answer', 'question_page');
}
);

Post as a guest















Required, but never shown

























0






active

oldest

votes








0






active

oldest

votes









active

oldest

votes






active

oldest

votes
















draft saved

draft discarded




















































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.




draft saved


draft discarded














StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f3133642%2fa-problem-on-path-connectedness-of-unit-ball-in-rr%23new-answer', 'question_page');
}
);

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







Popular posts from this blog

Nidaros erkebispedøme

Birsay

Was Woodrow Wilson really a Liberal?Was World War I a war of liberals against authoritarians?Founding Fathers...