Prove uniqueness and existence of ANY polynomial points/pairs The Next CEO of Stack...

What is the purpose of the Evocation wizard's Potent Cantrip feature?

If/When UK leaves the EU, can a future goverment conduct a referendum to join the EU?

Why does the UK parliament need a vote on the political declaration?

Written every which way

Won the lottery - how do I keep the money?

Does it take more energy to get to Venus or to Mars?

How fast would a person need to move to trick the eye?

Is "for causing autism in X" grammatical?

Do I need to enable Dev Hub in my PROD Org?

Why do we use the plural of movies in this phrase "We went to the movies last night."?

Why didn't Khan get resurrected in the Genesis Explosion?

Novel about a guy who is possessed by the divine essence and the world ends?

What does "Its cash flow is deeply negative" mean?

Between two walls

Is there a way to save my career from absolute disaster?

Contours of a clandestine nature

Limits on contract work without pre-agreed price/contract (UK)

What is the result of assigning to std::vector<T>::begin()?

Can I equip Skullclamp on a creature I am sacrificing?

What's the best way to handle refactoring a big file?

What exact does MIB represent in SNMP? How is it different from OID?

What was the first Unix version to run on a microcomputer?

Multiple labels for a single equation

Why do remote companies require working in the US?



Prove uniqueness and existence of ANY polynomial points/pairs



The Next CEO of Stack OverflowExplanation of Lagrange Interpolating PolynomialQuestion about Wantzel's proof of the necessary condition for compass/straightedge constructibilityFor a fixed degree, is there always a Lagrange polynomial below the original function?Uniform convergence of Lagrange polynomialsAlgorithm to compute Newton polynomial derivativeprove existence and uniqueness of the partial fraction decomposition of the polynomial ring over a fieldProperties of polynomials that are polynomial conditions on the coefficientsFinding coefficients of a polynomial in several variables.Existence and uniqueness of solutions for SDE'sProof of solution existence and its uniquenessMissing step in Galois theory proofs












0












$begingroup$


In the book "A Programmer's introduction to mathematics" by J Kun., page 15, it states:




Theorem 2.2: For any integer $n>=0$ and any list of $n+1$ points $(x_0,y_0),(x_1,y_1)...(x_n,y_n)$ in $mathbb{R^2}$ with $x_0 < x_1 < ... < x_n$, there exists a unique degree $n$ polynomial $p(x)$ such that $p(x_i)=y_i$ for all $i$.




As I was reading this, I thought: does this mean that if I make up any pairs of points, where $x_1 < x_n $, there will be a function that will satisfy it?



So I made these up:




(2,10),(3,15),(4,23),(5,30)




Which of course don't have a solution but do satisfy the constraint imposed on $x$ (in the theorem there is no constraint imposed on $y$) although they do have an approximation .



So my question is this, and forgive my noobiness,



1) is the statement exact and I'm missing something



OR



2) is this just normal math lingo and everyone knows that of course there won't be a solution for any sequence of pairs but if such a sequence is the output of a polynomial function, then, it will be the only one, ie. there will be no other polynomial function that will output the same exact sequence of pairs?



I lean toward option 2) but want to be absolutely sure I'm not missing something.










share|cite|improve this question









$endgroup$












  • $begingroup$
    1 is true and you are indeed missing something - note that the cubic here will have rational coefficients not necessarily integral
    $endgroup$
    – Conrad
    Mar 16 at 21:37










  • $begingroup$
    Thank you! Indeed, I hadn't realized it the coefficients could be rational! But still (and again forgive my noobiness) why can't an exact solution be found for such a 'simple' equation, ie one with four terms? It's sort of confusing that we can prove there is such a solution but we can't actually find it..
    $endgroup$
    – danoobis m
    Mar 16 at 23:58










  • $begingroup$
    We can find it by equating coefficients sure, just that computations can be complicated - here it's 4 linear equations with 4 unknowns but fairly high coefficients. The Lagrange interpolation formula does it also but it's fairly impractical as each term had a definite formula but you have to add 4 here and again computations explode fast - usually ad hoc computations should first be tried in specific examples
    $endgroup$
    – Conrad
    Mar 17 at 2:04
















0












$begingroup$


In the book "A Programmer's introduction to mathematics" by J Kun., page 15, it states:




Theorem 2.2: For any integer $n>=0$ and any list of $n+1$ points $(x_0,y_0),(x_1,y_1)...(x_n,y_n)$ in $mathbb{R^2}$ with $x_0 < x_1 < ... < x_n$, there exists a unique degree $n$ polynomial $p(x)$ such that $p(x_i)=y_i$ for all $i$.




As I was reading this, I thought: does this mean that if I make up any pairs of points, where $x_1 < x_n $, there will be a function that will satisfy it?



So I made these up:




(2,10),(3,15),(4,23),(5,30)




Which of course don't have a solution but do satisfy the constraint imposed on $x$ (in the theorem there is no constraint imposed on $y$) although they do have an approximation .



So my question is this, and forgive my noobiness,



1) is the statement exact and I'm missing something



OR



2) is this just normal math lingo and everyone knows that of course there won't be a solution for any sequence of pairs but if such a sequence is the output of a polynomial function, then, it will be the only one, ie. there will be no other polynomial function that will output the same exact sequence of pairs?



I lean toward option 2) but want to be absolutely sure I'm not missing something.










share|cite|improve this question









$endgroup$












  • $begingroup$
    1 is true and you are indeed missing something - note that the cubic here will have rational coefficients not necessarily integral
    $endgroup$
    – Conrad
    Mar 16 at 21:37










  • $begingroup$
    Thank you! Indeed, I hadn't realized it the coefficients could be rational! But still (and again forgive my noobiness) why can't an exact solution be found for such a 'simple' equation, ie one with four terms? It's sort of confusing that we can prove there is such a solution but we can't actually find it..
    $endgroup$
    – danoobis m
    Mar 16 at 23:58










  • $begingroup$
    We can find it by equating coefficients sure, just that computations can be complicated - here it's 4 linear equations with 4 unknowns but fairly high coefficients. The Lagrange interpolation formula does it also but it's fairly impractical as each term had a definite formula but you have to add 4 here and again computations explode fast - usually ad hoc computations should first be tried in specific examples
    $endgroup$
    – Conrad
    Mar 17 at 2:04














0












0








0





$begingroup$


In the book "A Programmer's introduction to mathematics" by J Kun., page 15, it states:




Theorem 2.2: For any integer $n>=0$ and any list of $n+1$ points $(x_0,y_0),(x_1,y_1)...(x_n,y_n)$ in $mathbb{R^2}$ with $x_0 < x_1 < ... < x_n$, there exists a unique degree $n$ polynomial $p(x)$ such that $p(x_i)=y_i$ for all $i$.




As I was reading this, I thought: does this mean that if I make up any pairs of points, where $x_1 < x_n $, there will be a function that will satisfy it?



So I made these up:




(2,10),(3,15),(4,23),(5,30)




Which of course don't have a solution but do satisfy the constraint imposed on $x$ (in the theorem there is no constraint imposed on $y$) although they do have an approximation .



So my question is this, and forgive my noobiness,



1) is the statement exact and I'm missing something



OR



2) is this just normal math lingo and everyone knows that of course there won't be a solution for any sequence of pairs but if such a sequence is the output of a polynomial function, then, it will be the only one, ie. there will be no other polynomial function that will output the same exact sequence of pairs?



I lean toward option 2) but want to be absolutely sure I'm not missing something.










share|cite|improve this question









$endgroup$




In the book "A Programmer's introduction to mathematics" by J Kun., page 15, it states:




Theorem 2.2: For any integer $n>=0$ and any list of $n+1$ points $(x_0,y_0),(x_1,y_1)...(x_n,y_n)$ in $mathbb{R^2}$ with $x_0 < x_1 < ... < x_n$, there exists a unique degree $n$ polynomial $p(x)$ such that $p(x_i)=y_i$ for all $i$.




As I was reading this, I thought: does this mean that if I make up any pairs of points, where $x_1 < x_n $, there will be a function that will satisfy it?



So I made these up:




(2,10),(3,15),(4,23),(5,30)




Which of course don't have a solution but do satisfy the constraint imposed on $x$ (in the theorem there is no constraint imposed on $y$) although they do have an approximation .



So my question is this, and forgive my noobiness,



1) is the statement exact and I'm missing something



OR



2) is this just normal math lingo and everyone knows that of course there won't be a solution for any sequence of pairs but if such a sequence is the output of a polynomial function, then, it will be the only one, ie. there will be no other polynomial function that will output the same exact sequence of pairs?



I lean toward option 2) but want to be absolutely sure I'm not missing something.







polynomials proof-explanation






share|cite|improve this question













share|cite|improve this question











share|cite|improve this question




share|cite|improve this question










asked Mar 16 at 17:12









danoobis mdanoobis m

32




32












  • $begingroup$
    1 is true and you are indeed missing something - note that the cubic here will have rational coefficients not necessarily integral
    $endgroup$
    – Conrad
    Mar 16 at 21:37










  • $begingroup$
    Thank you! Indeed, I hadn't realized it the coefficients could be rational! But still (and again forgive my noobiness) why can't an exact solution be found for such a 'simple' equation, ie one with four terms? It's sort of confusing that we can prove there is such a solution but we can't actually find it..
    $endgroup$
    – danoobis m
    Mar 16 at 23:58










  • $begingroup$
    We can find it by equating coefficients sure, just that computations can be complicated - here it's 4 linear equations with 4 unknowns but fairly high coefficients. The Lagrange interpolation formula does it also but it's fairly impractical as each term had a definite formula but you have to add 4 here and again computations explode fast - usually ad hoc computations should first be tried in specific examples
    $endgroup$
    – Conrad
    Mar 17 at 2:04


















  • $begingroup$
    1 is true and you are indeed missing something - note that the cubic here will have rational coefficients not necessarily integral
    $endgroup$
    – Conrad
    Mar 16 at 21:37










  • $begingroup$
    Thank you! Indeed, I hadn't realized it the coefficients could be rational! But still (and again forgive my noobiness) why can't an exact solution be found for such a 'simple' equation, ie one with four terms? It's sort of confusing that we can prove there is such a solution but we can't actually find it..
    $endgroup$
    – danoobis m
    Mar 16 at 23:58










  • $begingroup$
    We can find it by equating coefficients sure, just that computations can be complicated - here it's 4 linear equations with 4 unknowns but fairly high coefficients. The Lagrange interpolation formula does it also but it's fairly impractical as each term had a definite formula but you have to add 4 here and again computations explode fast - usually ad hoc computations should first be tried in specific examples
    $endgroup$
    – Conrad
    Mar 17 at 2:04
















$begingroup$
1 is true and you are indeed missing something - note that the cubic here will have rational coefficients not necessarily integral
$endgroup$
– Conrad
Mar 16 at 21:37




$begingroup$
1 is true and you are indeed missing something - note that the cubic here will have rational coefficients not necessarily integral
$endgroup$
– Conrad
Mar 16 at 21:37












$begingroup$
Thank you! Indeed, I hadn't realized it the coefficients could be rational! But still (and again forgive my noobiness) why can't an exact solution be found for such a 'simple' equation, ie one with four terms? It's sort of confusing that we can prove there is such a solution but we can't actually find it..
$endgroup$
– danoobis m
Mar 16 at 23:58




$begingroup$
Thank you! Indeed, I hadn't realized it the coefficients could be rational! But still (and again forgive my noobiness) why can't an exact solution be found for such a 'simple' equation, ie one with four terms? It's sort of confusing that we can prove there is such a solution but we can't actually find it..
$endgroup$
– danoobis m
Mar 16 at 23:58












$begingroup$
We can find it by equating coefficients sure, just that computations can be complicated - here it's 4 linear equations with 4 unknowns but fairly high coefficients. The Lagrange interpolation formula does it also but it's fairly impractical as each term had a definite formula but you have to add 4 here and again computations explode fast - usually ad hoc computations should first be tried in specific examples
$endgroup$
– Conrad
Mar 17 at 2:04




$begingroup$
We can find it by equating coefficients sure, just that computations can be complicated - here it's 4 linear equations with 4 unknowns but fairly high coefficients. The Lagrange interpolation formula does it also but it's fairly impractical as each term had a definite formula but you have to add 4 here and again computations explode fast - usually ad hoc computations should first be tried in specific examples
$endgroup$
– Conrad
Mar 17 at 2:04










1 Answer
1






active

oldest

votes


















0












$begingroup$

Lagrange polynomials are constructed such that they pass through a set of points ${(x_i,y_i)}_{i=1}^n$, with $x_1<ldots<x_n$.



The link has the proof, but in general terms, the polynomials are a sum of terms that are zero at all the other points except $x_i$, where that term has the value $y_i$.



You may also want to take a look at some explanation of Lagrange polynomials.






share|cite|improve this answer









$endgroup$













  • $begingroup$
    Thanks for that 2nd link, it is particularly helpful!
    $endgroup$
    – danoobis m
    Mar 17 at 0:04












  • $begingroup$
    You're welcome, @danoobis-m.
    $endgroup$
    – Ertxiem
    Mar 17 at 1:06














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%2f3150598%2fprove-uniqueness-and-existence-of-any-polynomial-points-pairs%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









0












$begingroup$

Lagrange polynomials are constructed such that they pass through a set of points ${(x_i,y_i)}_{i=1}^n$, with $x_1<ldots<x_n$.



The link has the proof, but in general terms, the polynomials are a sum of terms that are zero at all the other points except $x_i$, where that term has the value $y_i$.



You may also want to take a look at some explanation of Lagrange polynomials.






share|cite|improve this answer









$endgroup$













  • $begingroup$
    Thanks for that 2nd link, it is particularly helpful!
    $endgroup$
    – danoobis m
    Mar 17 at 0:04












  • $begingroup$
    You're welcome, @danoobis-m.
    $endgroup$
    – Ertxiem
    Mar 17 at 1:06


















0












$begingroup$

Lagrange polynomials are constructed such that they pass through a set of points ${(x_i,y_i)}_{i=1}^n$, with $x_1<ldots<x_n$.



The link has the proof, but in general terms, the polynomials are a sum of terms that are zero at all the other points except $x_i$, where that term has the value $y_i$.



You may also want to take a look at some explanation of Lagrange polynomials.






share|cite|improve this answer









$endgroup$













  • $begingroup$
    Thanks for that 2nd link, it is particularly helpful!
    $endgroup$
    – danoobis m
    Mar 17 at 0:04












  • $begingroup$
    You're welcome, @danoobis-m.
    $endgroup$
    – Ertxiem
    Mar 17 at 1:06
















0












0








0





$begingroup$

Lagrange polynomials are constructed such that they pass through a set of points ${(x_i,y_i)}_{i=1}^n$, with $x_1<ldots<x_n$.



The link has the proof, but in general terms, the polynomials are a sum of terms that are zero at all the other points except $x_i$, where that term has the value $y_i$.



You may also want to take a look at some explanation of Lagrange polynomials.






share|cite|improve this answer









$endgroup$



Lagrange polynomials are constructed such that they pass through a set of points ${(x_i,y_i)}_{i=1}^n$, with $x_1<ldots<x_n$.



The link has the proof, but in general terms, the polynomials are a sum of terms that are zero at all the other points except $x_i$, where that term has the value $y_i$.



You may also want to take a look at some explanation of Lagrange polynomials.







share|cite|improve this answer












share|cite|improve this answer



share|cite|improve this answer










answered Mar 16 at 18:08









ErtxiemErtxiem

55811




55811












  • $begingroup$
    Thanks for that 2nd link, it is particularly helpful!
    $endgroup$
    – danoobis m
    Mar 17 at 0:04












  • $begingroup$
    You're welcome, @danoobis-m.
    $endgroup$
    – Ertxiem
    Mar 17 at 1:06




















  • $begingroup$
    Thanks for that 2nd link, it is particularly helpful!
    $endgroup$
    – danoobis m
    Mar 17 at 0:04












  • $begingroup$
    You're welcome, @danoobis-m.
    $endgroup$
    – Ertxiem
    Mar 17 at 1:06


















$begingroup$
Thanks for that 2nd link, it is particularly helpful!
$endgroup$
– danoobis m
Mar 17 at 0:04






$begingroup$
Thanks for that 2nd link, it is particularly helpful!
$endgroup$
– danoobis m
Mar 17 at 0:04














$begingroup$
You're welcome, @danoobis-m.
$endgroup$
– Ertxiem
Mar 17 at 1:06






$begingroup$
You're welcome, @danoobis-m.
$endgroup$
– Ertxiem
Mar 17 at 1:06




















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%2f3150598%2fprove-uniqueness-and-existence-of-any-polynomial-points-pairs%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

六本木駅

Integral that is continuous and looks like it converges to a geometric seriesTesting if a geometric series converges by taking limit to infinitySummation of arithmetic-geometric series of higher orderGeometric series with polynomial exponentHow to Recognize a Geometric SeriesShowing an integral equality with series over the integersDiscontinuity of a series of continuous functionsReasons why a Series ConvergesSum of infinite geometric series with two terms in summationUsing geometric series for computing IntegralsLimit of geometric series sum when $r = 1$

Joseph Lister