Algebraic intuition behind inversion of circles












0












$begingroup$


I am struggling to understand inversions of shapes (namely, circles and lines) algebraically. For one, I understand how to apply inversions to general equations of circles and lines (by replacing all instances of the variables $x$ and $y$ with $1/x$ and $1/y$ respectively), but I can't seem to go the further level by applying this to, say, 2 tangent circles with inversions at point of tangency (or another point). Apparently,




  1. tangent circles with an inversion NOT at the point of tangency become the same tangent cirlces


  2. tangent circles with an inversion at the point of tangency become a pair of parallel lines perpendicular to the segment joining their centres



But, I cannot seem to formulate equations for these more complex and interacting cases.










share|cite|improve this question











$endgroup$












  • $begingroup$
    @Lubin yes you are right, my bad. I edited it.
    $endgroup$
    – helpneeded
    Dec 19 '18 at 18:08
















0












$begingroup$


I am struggling to understand inversions of shapes (namely, circles and lines) algebraically. For one, I understand how to apply inversions to general equations of circles and lines (by replacing all instances of the variables $x$ and $y$ with $1/x$ and $1/y$ respectively), but I can't seem to go the further level by applying this to, say, 2 tangent circles with inversions at point of tangency (or another point). Apparently,




  1. tangent circles with an inversion NOT at the point of tangency become the same tangent cirlces


  2. tangent circles with an inversion at the point of tangency become a pair of parallel lines perpendicular to the segment joining their centres



But, I cannot seem to formulate equations for these more complex and interacting cases.










share|cite|improve this question











$endgroup$












  • $begingroup$
    @Lubin yes you are right, my bad. I edited it.
    $endgroup$
    – helpneeded
    Dec 19 '18 at 18:08














0












0








0





$begingroup$


I am struggling to understand inversions of shapes (namely, circles and lines) algebraically. For one, I understand how to apply inversions to general equations of circles and lines (by replacing all instances of the variables $x$ and $y$ with $1/x$ and $1/y$ respectively), but I can't seem to go the further level by applying this to, say, 2 tangent circles with inversions at point of tangency (or another point). Apparently,




  1. tangent circles with an inversion NOT at the point of tangency become the same tangent cirlces


  2. tangent circles with an inversion at the point of tangency become a pair of parallel lines perpendicular to the segment joining their centres



But, I cannot seem to formulate equations for these more complex and interacting cases.










share|cite|improve this question











$endgroup$




I am struggling to understand inversions of shapes (namely, circles and lines) algebraically. For one, I understand how to apply inversions to general equations of circles and lines (by replacing all instances of the variables $x$ and $y$ with $1/x$ and $1/y$ respectively), but I can't seem to go the further level by applying this to, say, 2 tangent circles with inversions at point of tangency (or another point). Apparently,




  1. tangent circles with an inversion NOT at the point of tangency become the same tangent cirlces


  2. tangent circles with an inversion at the point of tangency become a pair of parallel lines perpendicular to the segment joining their centres



But, I cannot seem to formulate equations for these more complex and interacting cases.







geometry euclidean-geometry circle inversive-geometry






share|cite|improve this question















share|cite|improve this question













share|cite|improve this question




share|cite|improve this question








edited Dec 19 '18 at 18:18







helpneeded

















asked Dec 19 '18 at 17:46









helpneededhelpneeded

897




897












  • $begingroup$
    @Lubin yes you are right, my bad. I edited it.
    $endgroup$
    – helpneeded
    Dec 19 '18 at 18:08


















  • $begingroup$
    @Lubin yes you are right, my bad. I edited it.
    $endgroup$
    – helpneeded
    Dec 19 '18 at 18:08
















$begingroup$
@Lubin yes you are right, my bad. I edited it.
$endgroup$
– helpneeded
Dec 19 '18 at 18:08




$begingroup$
@Lubin yes you are right, my bad. I edited it.
$endgroup$
– helpneeded
Dec 19 '18 at 18:08










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%2f3046668%2falgebraic-intuition-behind-inversion-of-circles%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%2f3046668%2falgebraic-intuition-behind-inversion-of-circles%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

Quarter-circle Tiles

build a pushdown automaton that recognizes the reverse language of a given pushdown automaton?

Mont Emei