Alternatives in Farka's Lemma as boudaries












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I am attempting to solve a problem in the field of Economics, and for that purpose I have devised the following lemmas.



Lemma 1: Let $A(x)$ be a square matrix and let $x^*$ be such that $A(x^* )z=0$ has a nontrivial solution for $z$. Let $A(x)y(x)=b$, where $b>0$. Then $lim_{x rightarrow x^*} y(x)=infty$, where $infty$ is a vector where at least one entry is equal to infinity.



Lemma 2: Let $A(x)$ be a square matrix and let $x^*$ be such that $A(x^* )z=0$ has a nontrivial solution for $z$. Let $A(x)y(x)=b$, where $b>0$. Let $z$ have no zero entries. Then $lim_{x→x^*}y(x)=infty^{*}$, where $∞^*$ is a vector where all entries are equal to infinity.



I have look on many books to find these theorems or a perfected form of them, with no results. Can someone help?










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  • $begingroup$
    What exactly is the question?
    $endgroup$
    – littleO
    Jan 9 at 1:51










  • $begingroup$
    The question is whether you have seen this before and, if not, if it looks right to you.
    $endgroup$
    – a.giannel
    Jan 9 at 1:59


















0












$begingroup$


I am attempting to solve a problem in the field of Economics, and for that purpose I have devised the following lemmas.



Lemma 1: Let $A(x)$ be a square matrix and let $x^*$ be such that $A(x^* )z=0$ has a nontrivial solution for $z$. Let $A(x)y(x)=b$, where $b>0$. Then $lim_{x rightarrow x^*} y(x)=infty$, where $infty$ is a vector where at least one entry is equal to infinity.



Lemma 2: Let $A(x)$ be a square matrix and let $x^*$ be such that $A(x^* )z=0$ has a nontrivial solution for $z$. Let $A(x)y(x)=b$, where $b>0$. Let $z$ have no zero entries. Then $lim_{x→x^*}y(x)=infty^{*}$, where $∞^*$ is a vector where all entries are equal to infinity.



I have look on many books to find these theorems or a perfected form of them, with no results. Can someone help?










share|cite|improve this question











$endgroup$












  • $begingroup$
    What exactly is the question?
    $endgroup$
    – littleO
    Jan 9 at 1:51










  • $begingroup$
    The question is whether you have seen this before and, if not, if it looks right to you.
    $endgroup$
    – a.giannel
    Jan 9 at 1:59
















0












0








0





$begingroup$


I am attempting to solve a problem in the field of Economics, and for that purpose I have devised the following lemmas.



Lemma 1: Let $A(x)$ be a square matrix and let $x^*$ be such that $A(x^* )z=0$ has a nontrivial solution for $z$. Let $A(x)y(x)=b$, where $b>0$. Then $lim_{x rightarrow x^*} y(x)=infty$, where $infty$ is a vector where at least one entry is equal to infinity.



Lemma 2: Let $A(x)$ be a square matrix and let $x^*$ be such that $A(x^* )z=0$ has a nontrivial solution for $z$. Let $A(x)y(x)=b$, where $b>0$. Let $z$ have no zero entries. Then $lim_{x→x^*}y(x)=infty^{*}$, where $∞^*$ is a vector where all entries are equal to infinity.



I have look on many books to find these theorems or a perfected form of them, with no results. Can someone help?










share|cite|improve this question











$endgroup$




I am attempting to solve a problem in the field of Economics, and for that purpose I have devised the following lemmas.



Lemma 1: Let $A(x)$ be a square matrix and let $x^*$ be such that $A(x^* )z=0$ has a nontrivial solution for $z$. Let $A(x)y(x)=b$, where $b>0$. Then $lim_{x rightarrow x^*} y(x)=infty$, where $infty$ is a vector where at least one entry is equal to infinity.



Lemma 2: Let $A(x)$ be a square matrix and let $x^*$ be such that $A(x^* )z=0$ has a nontrivial solution for $z$. Let $A(x)y(x)=b$, where $b>0$. Let $z$ have no zero entries. Then $lim_{x→x^*}y(x)=infty^{*}$, where $∞^*$ is a vector where all entries are equal to infinity.



I have look on many books to find these theorems or a perfected form of them, with no results. Can someone help?







matrices matrix-equations matrix-calculus






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share|cite|improve this question













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share|cite|improve this question








edited Jan 9 at 2:38









Gaby Alfonso

697315




697315










asked Jan 9 at 1:40









a.giannela.giannel

162




162












  • $begingroup$
    What exactly is the question?
    $endgroup$
    – littleO
    Jan 9 at 1:51










  • $begingroup$
    The question is whether you have seen this before and, if not, if it looks right to you.
    $endgroup$
    – a.giannel
    Jan 9 at 1:59




















  • $begingroup$
    What exactly is the question?
    $endgroup$
    – littleO
    Jan 9 at 1:51










  • $begingroup$
    The question is whether you have seen this before and, if not, if it looks right to you.
    $endgroup$
    – a.giannel
    Jan 9 at 1:59


















$begingroup$
What exactly is the question?
$endgroup$
– littleO
Jan 9 at 1:51




$begingroup$
What exactly is the question?
$endgroup$
– littleO
Jan 9 at 1:51












$begingroup$
The question is whether you have seen this before and, if not, if it looks right to you.
$endgroup$
– a.giannel
Jan 9 at 1:59






$begingroup$
The question is whether you have seen this before and, if not, if it looks right to you.
$endgroup$
– a.giannel
Jan 9 at 1:59












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