How can lists/vectors in $mathbb{R}^2$ be thought of as functions?












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It's written in my linear algebra textbook that $mathbb{R}^S$ is the set of all possible functions $f: S to mathbb{R}$, I fail to see how this applies when $S=2=lbrace {0,1} rbrace$ as it's not clear to me how a vector like $(72,15)$ is a function










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  • 4




    $begingroup$
    I think $2={0,1}$, and then $(72,15)$ represents the function where $f(0)=72$ and $f(1)=15$.
    $endgroup$
    – Cheerful Parsnip
    Jan 31 at 18:31






  • 1




    $begingroup$
    My comment should answer your question. Is there anything unclear about it?
    $endgroup$
    – Cheerful Parsnip
    Jan 31 at 18:39






  • 1




    $begingroup$
    @CheerfulParsnip If your comment answers the question, you should make it an answer! I’d gladly +1
    $endgroup$
    – Santana Afton
    Jan 31 at 22:50
















1












$begingroup$


It's written in my linear algebra textbook that $mathbb{R}^S$ is the set of all possible functions $f: S to mathbb{R}$, I fail to see how this applies when $S=2=lbrace {0,1} rbrace$ as it's not clear to me how a vector like $(72,15)$ is a function










share|cite|improve this question











$endgroup$








  • 4




    $begingroup$
    I think $2={0,1}$, and then $(72,15)$ represents the function where $f(0)=72$ and $f(1)=15$.
    $endgroup$
    – Cheerful Parsnip
    Jan 31 at 18:31






  • 1




    $begingroup$
    My comment should answer your question. Is there anything unclear about it?
    $endgroup$
    – Cheerful Parsnip
    Jan 31 at 18:39






  • 1




    $begingroup$
    @CheerfulParsnip If your comment answers the question, you should make it an answer! I’d gladly +1
    $endgroup$
    – Santana Afton
    Jan 31 at 22:50














1












1








1





$begingroup$


It's written in my linear algebra textbook that $mathbb{R}^S$ is the set of all possible functions $f: S to mathbb{R}$, I fail to see how this applies when $S=2=lbrace {0,1} rbrace$ as it's not clear to me how a vector like $(72,15)$ is a function










share|cite|improve this question











$endgroup$




It's written in my linear algebra textbook that $mathbb{R}^S$ is the set of all possible functions $f: S to mathbb{R}$, I fail to see how this applies when $S=2=lbrace {0,1} rbrace$ as it's not clear to me how a vector like $(72,15)$ is a function







linear-algebra






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share|cite|improve this question













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share|cite|improve this question








edited Feb 1 at 5:49







user168651

















asked Jan 31 at 18:28









user168651user168651

62




62








  • 4




    $begingroup$
    I think $2={0,1}$, and then $(72,15)$ represents the function where $f(0)=72$ and $f(1)=15$.
    $endgroup$
    – Cheerful Parsnip
    Jan 31 at 18:31






  • 1




    $begingroup$
    My comment should answer your question. Is there anything unclear about it?
    $endgroup$
    – Cheerful Parsnip
    Jan 31 at 18:39






  • 1




    $begingroup$
    @CheerfulParsnip If your comment answers the question, you should make it an answer! I’d gladly +1
    $endgroup$
    – Santana Afton
    Jan 31 at 22:50














  • 4




    $begingroup$
    I think $2={0,1}$, and then $(72,15)$ represents the function where $f(0)=72$ and $f(1)=15$.
    $endgroup$
    – Cheerful Parsnip
    Jan 31 at 18:31






  • 1




    $begingroup$
    My comment should answer your question. Is there anything unclear about it?
    $endgroup$
    – Cheerful Parsnip
    Jan 31 at 18:39






  • 1




    $begingroup$
    @CheerfulParsnip If your comment answers the question, you should make it an answer! I’d gladly +1
    $endgroup$
    – Santana Afton
    Jan 31 at 22:50








4




4




$begingroup$
I think $2={0,1}$, and then $(72,15)$ represents the function where $f(0)=72$ and $f(1)=15$.
$endgroup$
– Cheerful Parsnip
Jan 31 at 18:31




$begingroup$
I think $2={0,1}$, and then $(72,15)$ represents the function where $f(0)=72$ and $f(1)=15$.
$endgroup$
– Cheerful Parsnip
Jan 31 at 18:31




1




1




$begingroup$
My comment should answer your question. Is there anything unclear about it?
$endgroup$
– Cheerful Parsnip
Jan 31 at 18:39




$begingroup$
My comment should answer your question. Is there anything unclear about it?
$endgroup$
– Cheerful Parsnip
Jan 31 at 18:39




1




1




$begingroup$
@CheerfulParsnip If your comment answers the question, you should make it an answer! I’d gladly +1
$endgroup$
– Santana Afton
Jan 31 at 22:50




$begingroup$
@CheerfulParsnip If your comment answers the question, you should make it an answer! I’d gladly +1
$endgroup$
– Santana Afton
Jan 31 at 22:50










1 Answer
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$begingroup$

You can think of $mathbb R^n$ as lists of numbers but you can also think of it as functions $fcolon {1,ldots,n}to mathbb R$ where the $j$th coordinate can be regarded as $f(j)$. Then, if $|S|=s$ we have that $mathbb R^Scong mathbb R^s$.






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  • 1




    $begingroup$
    Small edit - changed $mathbb{R}^2$ to $mathbb{R}^n$ since you used $n$ afterwards.
    $endgroup$
    – Sambo
    Jan 31 at 23:10










  • $begingroup$
    @Sambo, oops. Thanks.
    $endgroup$
    – Cheerful Parsnip
    Jan 31 at 23:14












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1 Answer
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active

oldest

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1 Answer
1






active

oldest

votes









active

oldest

votes






active

oldest

votes









5












$begingroup$

You can think of $mathbb R^n$ as lists of numbers but you can also think of it as functions $fcolon {1,ldots,n}to mathbb R$ where the $j$th coordinate can be regarded as $f(j)$. Then, if $|S|=s$ we have that $mathbb R^Scong mathbb R^s$.






share|cite|improve this answer











$endgroup$









  • 1




    $begingroup$
    Small edit - changed $mathbb{R}^2$ to $mathbb{R}^n$ since you used $n$ afterwards.
    $endgroup$
    – Sambo
    Jan 31 at 23:10










  • $begingroup$
    @Sambo, oops. Thanks.
    $endgroup$
    – Cheerful Parsnip
    Jan 31 at 23:14
















5












$begingroup$

You can think of $mathbb R^n$ as lists of numbers but you can also think of it as functions $fcolon {1,ldots,n}to mathbb R$ where the $j$th coordinate can be regarded as $f(j)$. Then, if $|S|=s$ we have that $mathbb R^Scong mathbb R^s$.






share|cite|improve this answer











$endgroup$









  • 1




    $begingroup$
    Small edit - changed $mathbb{R}^2$ to $mathbb{R}^n$ since you used $n$ afterwards.
    $endgroup$
    – Sambo
    Jan 31 at 23:10










  • $begingroup$
    @Sambo, oops. Thanks.
    $endgroup$
    – Cheerful Parsnip
    Jan 31 at 23:14














5












5








5





$begingroup$

You can think of $mathbb R^n$ as lists of numbers but you can also think of it as functions $fcolon {1,ldots,n}to mathbb R$ where the $j$th coordinate can be regarded as $f(j)$. Then, if $|S|=s$ we have that $mathbb R^Scong mathbb R^s$.






share|cite|improve this answer











$endgroup$



You can think of $mathbb R^n$ as lists of numbers but you can also think of it as functions $fcolon {1,ldots,n}to mathbb R$ where the $j$th coordinate can be regarded as $f(j)$. Then, if $|S|=s$ we have that $mathbb R^Scong mathbb R^s$.







share|cite|improve this answer














share|cite|improve this answer



share|cite|improve this answer








edited Jan 31 at 23:09









Sambo

2,3012532




2,3012532










answered Jan 31 at 23:03









Cheerful ParsnipCheerful Parsnip

21.2k23598




21.2k23598








  • 1




    $begingroup$
    Small edit - changed $mathbb{R}^2$ to $mathbb{R}^n$ since you used $n$ afterwards.
    $endgroup$
    – Sambo
    Jan 31 at 23:10










  • $begingroup$
    @Sambo, oops. Thanks.
    $endgroup$
    – Cheerful Parsnip
    Jan 31 at 23:14














  • 1




    $begingroup$
    Small edit - changed $mathbb{R}^2$ to $mathbb{R}^n$ since you used $n$ afterwards.
    $endgroup$
    – Sambo
    Jan 31 at 23:10










  • $begingroup$
    @Sambo, oops. Thanks.
    $endgroup$
    – Cheerful Parsnip
    Jan 31 at 23:14








1




1




$begingroup$
Small edit - changed $mathbb{R}^2$ to $mathbb{R}^n$ since you used $n$ afterwards.
$endgroup$
– Sambo
Jan 31 at 23:10




$begingroup$
Small edit - changed $mathbb{R}^2$ to $mathbb{R}^n$ since you used $n$ afterwards.
$endgroup$
– Sambo
Jan 31 at 23:10












$begingroup$
@Sambo, oops. Thanks.
$endgroup$
– Cheerful Parsnip
Jan 31 at 23:14




$begingroup$
@Sambo, oops. Thanks.
$endgroup$
– Cheerful Parsnip
Jan 31 at 23:14


















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