Prove that there is a basis for the $n$th degree polynomial vector space consisting $only$ of $n$th degree polynomials.
Clash Royale CLAN TAG#URR8PPP
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I tried looking around for an answer to this question, but I couldn't find anything specific enough. I'm thinking I need to use either Cartesian products or subspace sums to produce such a vector space, however I'm still fuzzy on how to actually implement it.
Any help would be great!
linear-algebra polynomials vector-spaces
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up vote
1
down vote
favorite
I tried looking around for an answer to this question, but I couldn't find anything specific enough. I'm thinking I need to use either Cartesian products or subspace sums to produce such a vector space, however I'm still fuzzy on how to actually implement it.
Any help would be great!
linear-algebra polynomials vector-spaces
What is the $n$-th degree polynomial vector space? Is that the vector space of polynomials (coefficients in some field) whose degree is at most $n$?
â Dave
Sep 10 at 18:56
Yes, that's my understanding. My text uses the notation ð½[$x$;$n$], without any explanation as to how it should be read, unfortunately.
â Silverwing171
Sep 10 at 19:00
Hint: if $v_1,v_2,dots,v_n$ is a basis for a vector space, then so is $v_1+v_n,v_2,dots,v_n$.
â amd
Sep 10 at 22:58
add a comment |Â
up vote
1
down vote
favorite
up vote
1
down vote
favorite
I tried looking around for an answer to this question, but I couldn't find anything specific enough. I'm thinking I need to use either Cartesian products or subspace sums to produce such a vector space, however I'm still fuzzy on how to actually implement it.
Any help would be great!
linear-algebra polynomials vector-spaces
I tried looking around for an answer to this question, but I couldn't find anything specific enough. I'm thinking I need to use either Cartesian products or subspace sums to produce such a vector space, however I'm still fuzzy on how to actually implement it.
Any help would be great!
linear-algebra polynomials vector-spaces
linear-algebra polynomials vector-spaces
asked Sep 10 at 18:53
Silverwing171
82
82
What is the $n$-th degree polynomial vector space? Is that the vector space of polynomials (coefficients in some field) whose degree is at most $n$?
â Dave
Sep 10 at 18:56
Yes, that's my understanding. My text uses the notation ð½[$x$;$n$], without any explanation as to how it should be read, unfortunately.
â Silverwing171
Sep 10 at 19:00
Hint: if $v_1,v_2,dots,v_n$ is a basis for a vector space, then so is $v_1+v_n,v_2,dots,v_n$.
â amd
Sep 10 at 22:58
add a comment |Â
What is the $n$-th degree polynomial vector space? Is that the vector space of polynomials (coefficients in some field) whose degree is at most $n$?
â Dave
Sep 10 at 18:56
Yes, that's my understanding. My text uses the notation ð½[$x$;$n$], without any explanation as to how it should be read, unfortunately.
â Silverwing171
Sep 10 at 19:00
Hint: if $v_1,v_2,dots,v_n$ is a basis for a vector space, then so is $v_1+v_n,v_2,dots,v_n$.
â amd
Sep 10 at 22:58
What is the $n$-th degree polynomial vector space? Is that the vector space of polynomials (coefficients in some field) whose degree is at most $n$?
â Dave
Sep 10 at 18:56
What is the $n$-th degree polynomial vector space? Is that the vector space of polynomials (coefficients in some field) whose degree is at most $n$?
â Dave
Sep 10 at 18:56
Yes, that's my understanding. My text uses the notation ð½[$x$;$n$], without any explanation as to how it should be read, unfortunately.
â Silverwing171
Sep 10 at 19:00
Yes, that's my understanding. My text uses the notation ð½[$x$;$n$], without any explanation as to how it should be read, unfortunately.
â Silverwing171
Sep 10 at 19:00
Hint: if $v_1,v_2,dots,v_n$ is a basis for a vector space, then so is $v_1+v_n,v_2,dots,v_n$.
â amd
Sep 10 at 22:58
Hint: if $v_1,v_2,dots,v_n$ is a basis for a vector space, then so is $v_1+v_n,v_2,dots,v_n$.
â amd
Sep 10 at 22:58
add a comment |Â
2 Answers
2
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oldest
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0
down vote
accepted
Hint:
We know that $1, x, x^2, ldots, x^n$ is a basis for your space. But then $$1+x^n, x+x^n, x^2+x^n, ldots, 2x^n$$
is also a basis for your space.
add a comment |Â
up vote
0
down vote
Pick any basis $f_1, ldots, f_n, f_n+1$. At least one of these polynomials must have degree exactly $n$, otherwise $x^n$ would not be in the generated subspace.
WLOG $deg f_1 =n$.
If some of the other basis vectors have smaller degree, add $f_1$ to them (and only to those with degree strictly less than $n$).
That yields a solution you were looking for.
add a comment |Â
2 Answers
2
active
oldest
votes
2 Answers
2
active
oldest
votes
active
oldest
votes
active
oldest
votes
up vote
0
down vote
accepted
Hint:
We know that $1, x, x^2, ldots, x^n$ is a basis for your space. But then $$1+x^n, x+x^n, x^2+x^n, ldots, 2x^n$$
is also a basis for your space.
add a comment |Â
up vote
0
down vote
accepted
Hint:
We know that $1, x, x^2, ldots, x^n$ is a basis for your space. But then $$1+x^n, x+x^n, x^2+x^n, ldots, 2x^n$$
is also a basis for your space.
add a comment |Â
up vote
0
down vote
accepted
up vote
0
down vote
accepted
Hint:
We know that $1, x, x^2, ldots, x^n$ is a basis for your space. But then $$1+x^n, x+x^n, x^2+x^n, ldots, 2x^n$$
is also a basis for your space.
Hint:
We know that $1, x, x^2, ldots, x^n$ is a basis for your space. But then $$1+x^n, x+x^n, x^2+x^n, ldots, 2x^n$$
is also a basis for your space.
answered Sep 10 at 19:44
mechanodroid
24.7k62245
24.7k62245
add a comment |Â
add a comment |Â
up vote
0
down vote
Pick any basis $f_1, ldots, f_n, f_n+1$. At least one of these polynomials must have degree exactly $n$, otherwise $x^n$ would not be in the generated subspace.
WLOG $deg f_1 =n$.
If some of the other basis vectors have smaller degree, add $f_1$ to them (and only to those with degree strictly less than $n$).
That yields a solution you were looking for.
add a comment |Â
up vote
0
down vote
Pick any basis $f_1, ldots, f_n, f_n+1$. At least one of these polynomials must have degree exactly $n$, otherwise $x^n$ would not be in the generated subspace.
WLOG $deg f_1 =n$.
If some of the other basis vectors have smaller degree, add $f_1$ to them (and only to those with degree strictly less than $n$).
That yields a solution you were looking for.
add a comment |Â
up vote
0
down vote
up vote
0
down vote
Pick any basis $f_1, ldots, f_n, f_n+1$. At least one of these polynomials must have degree exactly $n$, otherwise $x^n$ would not be in the generated subspace.
WLOG $deg f_1 =n$.
If some of the other basis vectors have smaller degree, add $f_1$ to them (and only to those with degree strictly less than $n$).
That yields a solution you were looking for.
Pick any basis $f_1, ldots, f_n, f_n+1$. At least one of these polynomials must have degree exactly $n$, otherwise $x^n$ would not be in the generated subspace.
WLOG $deg f_1 =n$.
If some of the other basis vectors have smaller degree, add $f_1$ to them (and only to those with degree strictly less than $n$).
That yields a solution you were looking for.
answered Sep 10 at 19:09
A. Pongrácz
4,465725
4,465725
add a comment |Â
add a comment |Â
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What is the $n$-th degree polynomial vector space? Is that the vector space of polynomials (coefficients in some field) whose degree is at most $n$?
â Dave
Sep 10 at 18:56
Yes, that's my understanding. My text uses the notation ð½[$x$;$n$], without any explanation as to how it should be read, unfortunately.
â Silverwing171
Sep 10 at 19:00
Hint: if $v_1,v_2,dots,v_n$ is a basis for a vector space, then so is $v_1+v_n,v_2,dots,v_n$.
â amd
Sep 10 at 22:58