Root of an quadratic equation











up vote
0
down vote

favorite












I have the following quadratic equation :



$m^2 + m(p-1/l) - (Omega_x^2 + Omega_y^2)=0$



I would like to get the solution in terms of $Omega_x, Omega_y$ with some approximations i.e. neglecting $(p-1/l)$ term.



Is it possible to express $mapproxOmega_x + Omega_y$ ? or any other form. Since I do not want roots in my approximated solution.



Thanks










share|cite|improve this question
























  • Why you don't just use the Quadratic formula? en.wikipedia.org/wiki/Quadratic_formula
    – Stockfish
    Nov 26 at 10:41










  • if you neglect the $m(p−1/l)$ term then your equation becomes $m^2 -(Omega_x^2 + Omega_y^2)=0$. Thus $$m = pmsqrt(Omega_x^2 + Omega_y^2)$$
    – TheD0ubleT
    Nov 26 at 10:43












  • @TheD0ubleT. Exactly, but I would like to avoid square root.
    – newstudent
    Nov 26 at 10:44










  • @newstudent In that case you can use a Taylor expansion if $Omega_y << Omega_x$ (or the other way around) $$m = Omega_xsqrt(1 + (frac{Omega_y}{Omega_x})^2)approxOmega_x(1+(frac{Omega_y}{2Omega_x}))$$
    – TheD0ubleT
    Nov 26 at 10:51

















up vote
0
down vote

favorite












I have the following quadratic equation :



$m^2 + m(p-1/l) - (Omega_x^2 + Omega_y^2)=0$



I would like to get the solution in terms of $Omega_x, Omega_y$ with some approximations i.e. neglecting $(p-1/l)$ term.



Is it possible to express $mapproxOmega_x + Omega_y$ ? or any other form. Since I do not want roots in my approximated solution.



Thanks










share|cite|improve this question
























  • Why you don't just use the Quadratic formula? en.wikipedia.org/wiki/Quadratic_formula
    – Stockfish
    Nov 26 at 10:41










  • if you neglect the $m(p−1/l)$ term then your equation becomes $m^2 -(Omega_x^2 + Omega_y^2)=0$. Thus $$m = pmsqrt(Omega_x^2 + Omega_y^2)$$
    – TheD0ubleT
    Nov 26 at 10:43












  • @TheD0ubleT. Exactly, but I would like to avoid square root.
    – newstudent
    Nov 26 at 10:44










  • @newstudent In that case you can use a Taylor expansion if $Omega_y << Omega_x$ (or the other way around) $$m = Omega_xsqrt(1 + (frac{Omega_y}{Omega_x})^2)approxOmega_x(1+(frac{Omega_y}{2Omega_x}))$$
    – TheD0ubleT
    Nov 26 at 10:51















up vote
0
down vote

favorite









up vote
0
down vote

favorite











I have the following quadratic equation :



$m^2 + m(p-1/l) - (Omega_x^2 + Omega_y^2)=0$



I would like to get the solution in terms of $Omega_x, Omega_y$ with some approximations i.e. neglecting $(p-1/l)$ term.



Is it possible to express $mapproxOmega_x + Omega_y$ ? or any other form. Since I do not want roots in my approximated solution.



Thanks










share|cite|improve this question















I have the following quadratic equation :



$m^2 + m(p-1/l) - (Omega_x^2 + Omega_y^2)=0$



I would like to get the solution in terms of $Omega_x, Omega_y$ with some approximations i.e. neglecting $(p-1/l)$ term.



Is it possible to express $mapproxOmega_x + Omega_y$ ? or any other form. Since I do not want roots in my approximated solution.



Thanks







roots quadratics approximation






share|cite|improve this question















share|cite|improve this question













share|cite|improve this question




share|cite|improve this question








edited Nov 26 at 10:53

























asked Nov 26 at 10:34









newstudent

226




226












  • Why you don't just use the Quadratic formula? en.wikipedia.org/wiki/Quadratic_formula
    – Stockfish
    Nov 26 at 10:41










  • if you neglect the $m(p−1/l)$ term then your equation becomes $m^2 -(Omega_x^2 + Omega_y^2)=0$. Thus $$m = pmsqrt(Omega_x^2 + Omega_y^2)$$
    – TheD0ubleT
    Nov 26 at 10:43












  • @TheD0ubleT. Exactly, but I would like to avoid square root.
    – newstudent
    Nov 26 at 10:44










  • @newstudent In that case you can use a Taylor expansion if $Omega_y << Omega_x$ (or the other way around) $$m = Omega_xsqrt(1 + (frac{Omega_y}{Omega_x})^2)approxOmega_x(1+(frac{Omega_y}{2Omega_x}))$$
    – TheD0ubleT
    Nov 26 at 10:51




















  • Why you don't just use the Quadratic formula? en.wikipedia.org/wiki/Quadratic_formula
    – Stockfish
    Nov 26 at 10:41










  • if you neglect the $m(p−1/l)$ term then your equation becomes $m^2 -(Omega_x^2 + Omega_y^2)=0$. Thus $$m = pmsqrt(Omega_x^2 + Omega_y^2)$$
    – TheD0ubleT
    Nov 26 at 10:43












  • @TheD0ubleT. Exactly, but I would like to avoid square root.
    – newstudent
    Nov 26 at 10:44










  • @newstudent In that case you can use a Taylor expansion if $Omega_y << Omega_x$ (or the other way around) $$m = Omega_xsqrt(1 + (frac{Omega_y}{Omega_x})^2)approxOmega_x(1+(frac{Omega_y}{2Omega_x}))$$
    – TheD0ubleT
    Nov 26 at 10:51


















Why you don't just use the Quadratic formula? en.wikipedia.org/wiki/Quadratic_formula
– Stockfish
Nov 26 at 10:41




Why you don't just use the Quadratic formula? en.wikipedia.org/wiki/Quadratic_formula
– Stockfish
Nov 26 at 10:41












if you neglect the $m(p−1/l)$ term then your equation becomes $m^2 -(Omega_x^2 + Omega_y^2)=0$. Thus $$m = pmsqrt(Omega_x^2 + Omega_y^2)$$
– TheD0ubleT
Nov 26 at 10:43






if you neglect the $m(p−1/l)$ term then your equation becomes $m^2 -(Omega_x^2 + Omega_y^2)=0$. Thus $$m = pmsqrt(Omega_x^2 + Omega_y^2)$$
– TheD0ubleT
Nov 26 at 10:43














@TheD0ubleT. Exactly, but I would like to avoid square root.
– newstudent
Nov 26 at 10:44




@TheD0ubleT. Exactly, but I would like to avoid square root.
– newstudent
Nov 26 at 10:44












@newstudent In that case you can use a Taylor expansion if $Omega_y << Omega_x$ (or the other way around) $$m = Omega_xsqrt(1 + (frac{Omega_y}{Omega_x})^2)approxOmega_x(1+(frac{Omega_y}{2Omega_x}))$$
– TheD0ubleT
Nov 26 at 10:51






@newstudent In that case you can use a Taylor expansion if $Omega_y << Omega_x$ (or the other way around) $$m = Omega_xsqrt(1 + (frac{Omega_y}{Omega_x})^2)approxOmega_x(1+(frac{Omega_y}{2Omega_x}))$$
– TheD0ubleT
Nov 26 at 10:51












1 Answer
1






active

oldest

votes

















up vote
1
down vote



accepted










You can use a binomial approximation for the square root, otherwise there's not way around it. If $p- 1 / l approx 0$ and $Omega_x > Omega_y$ then



$$
mapprox (Omega_x^2 + Omega_y^2)^{1/2} = Omega_xleft[1 + left(frac{Omega_y}{Omega_x}right)^2 right]^{1/2} approx Omega_x left[1 + frac{1}{2}left(frac{Omega_y}{Omega_x}right)^2 - frac{1}{8}left(frac{Omega_y}{Omega_x}right)^4 + cdots right]
$$






share|cite|improve this answer





















  • Thanks. I think this is what I was looking for.
    – newstudent
    Nov 26 at 10:54










  • @newstudent Happy to help
    – caverac
    Nov 26 at 10:55











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',
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%2f3014168%2froot-of-an-quadratic-equation%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








up vote
1
down vote



accepted










You can use a binomial approximation for the square root, otherwise there's not way around it. If $p- 1 / l approx 0$ and $Omega_x > Omega_y$ then



$$
mapprox (Omega_x^2 + Omega_y^2)^{1/2} = Omega_xleft[1 + left(frac{Omega_y}{Omega_x}right)^2 right]^{1/2} approx Omega_x left[1 + frac{1}{2}left(frac{Omega_y}{Omega_x}right)^2 - frac{1}{8}left(frac{Omega_y}{Omega_x}right)^4 + cdots right]
$$






share|cite|improve this answer





















  • Thanks. I think this is what I was looking for.
    – newstudent
    Nov 26 at 10:54










  • @newstudent Happy to help
    – caverac
    Nov 26 at 10:55















up vote
1
down vote



accepted










You can use a binomial approximation for the square root, otherwise there's not way around it. If $p- 1 / l approx 0$ and $Omega_x > Omega_y$ then



$$
mapprox (Omega_x^2 + Omega_y^2)^{1/2} = Omega_xleft[1 + left(frac{Omega_y}{Omega_x}right)^2 right]^{1/2} approx Omega_x left[1 + frac{1}{2}left(frac{Omega_y}{Omega_x}right)^2 - frac{1}{8}left(frac{Omega_y}{Omega_x}right)^4 + cdots right]
$$






share|cite|improve this answer





















  • Thanks. I think this is what I was looking for.
    – newstudent
    Nov 26 at 10:54










  • @newstudent Happy to help
    – caverac
    Nov 26 at 10:55













up vote
1
down vote



accepted







up vote
1
down vote



accepted






You can use a binomial approximation for the square root, otherwise there's not way around it. If $p- 1 / l approx 0$ and $Omega_x > Omega_y$ then



$$
mapprox (Omega_x^2 + Omega_y^2)^{1/2} = Omega_xleft[1 + left(frac{Omega_y}{Omega_x}right)^2 right]^{1/2} approx Omega_x left[1 + frac{1}{2}left(frac{Omega_y}{Omega_x}right)^2 - frac{1}{8}left(frac{Omega_y}{Omega_x}right)^4 + cdots right]
$$






share|cite|improve this answer












You can use a binomial approximation for the square root, otherwise there's not way around it. If $p- 1 / l approx 0$ and $Omega_x > Omega_y$ then



$$
mapprox (Omega_x^2 + Omega_y^2)^{1/2} = Omega_xleft[1 + left(frac{Omega_y}{Omega_x}right)^2 right]^{1/2} approx Omega_x left[1 + frac{1}{2}left(frac{Omega_y}{Omega_x}right)^2 - frac{1}{8}left(frac{Omega_y}{Omega_x}right)^4 + cdots right]
$$







share|cite|improve this answer












share|cite|improve this answer



share|cite|improve this answer










answered Nov 26 at 10:51









caverac

12.4k21027




12.4k21027












  • Thanks. I think this is what I was looking for.
    – newstudent
    Nov 26 at 10:54










  • @newstudent Happy to help
    – caverac
    Nov 26 at 10:55


















  • Thanks. I think this is what I was looking for.
    – newstudent
    Nov 26 at 10:54










  • @newstudent Happy to help
    – caverac
    Nov 26 at 10:55
















Thanks. I think this is what I was looking for.
– newstudent
Nov 26 at 10:54




Thanks. I think this is what I was looking for.
– newstudent
Nov 26 at 10:54












@newstudent Happy to help
– caverac
Nov 26 at 10:55




@newstudent Happy to help
– caverac
Nov 26 at 10:55


















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.





Some of your past answers have not been well-received, and you're in danger of being blocked from answering.


Please pay close attention to the following guidance:


  • 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.


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%2f3014168%2froot-of-an-quadratic-equation%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

Berounka

Different font size/position of beamer's navigation symbols template's content depending on regular/plain...

Sphinx de Gizeh