What is the maximal domain of these functions?
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Need help figuring out, how to find the maximal domains of functions
$f(x) = frac{x^3-x}{2x^2+1}$
$f(x) = frac{x^2-5x+6}{x-2}$
functions
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add a comment |
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Need help figuring out, how to find the maximal domains of functions
$f(x) = frac{x^3-x}{2x^2+1}$
$f(x) = frac{x^2-5x+6}{x-2}$
functions
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I guess $f$ should be dependant on $y$ and $z$, not on $x$? Considering finding the domain: The domain of $f$ is the set of arguments for which $f$ is well-defined. So you need to ask yourself "when is $frac{a}{b}$ not well-defined?".
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– Piwi
Oct 11 '15 at 17:28
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please clarify the domain of function argument
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– pointguard0
Aug 4 '18 at 13:18
add a comment |
$begingroup$
Need help figuring out, how to find the maximal domains of functions
$f(x) = frac{x^3-x}{2x^2+1}$
$f(x) = frac{x^2-5x+6}{x-2}$
functions
$endgroup$
Need help figuring out, how to find the maximal domains of functions
$f(x) = frac{x^3-x}{2x^2+1}$
$f(x) = frac{x^2-5x+6}{x-2}$
functions
functions
edited Aug 4 '18 at 13:11
pointguard0
1,4581021
1,4581021
asked Oct 11 '15 at 17:05
Chris SmithChris Smith
611
611
$begingroup$
I guess $f$ should be dependant on $y$ and $z$, not on $x$? Considering finding the domain: The domain of $f$ is the set of arguments for which $f$ is well-defined. So you need to ask yourself "when is $frac{a}{b}$ not well-defined?".
$endgroup$
– Piwi
Oct 11 '15 at 17:28
$begingroup$
please clarify the domain of function argument
$endgroup$
– pointguard0
Aug 4 '18 at 13:18
add a comment |
$begingroup$
I guess $f$ should be dependant on $y$ and $z$, not on $x$? Considering finding the domain: The domain of $f$ is the set of arguments for which $f$ is well-defined. So you need to ask yourself "when is $frac{a}{b}$ not well-defined?".
$endgroup$
– Piwi
Oct 11 '15 at 17:28
$begingroup$
please clarify the domain of function argument
$endgroup$
– pointguard0
Aug 4 '18 at 13:18
$begingroup$
I guess $f$ should be dependant on $y$ and $z$, not on $x$? Considering finding the domain: The domain of $f$ is the set of arguments for which $f$ is well-defined. So you need to ask yourself "when is $frac{a}{b}$ not well-defined?".
$endgroup$
– Piwi
Oct 11 '15 at 17:28
$begingroup$
I guess $f$ should be dependant on $y$ and $z$, not on $x$? Considering finding the domain: The domain of $f$ is the set of arguments for which $f$ is well-defined. So you need to ask yourself "when is $frac{a}{b}$ not well-defined?".
$endgroup$
– Piwi
Oct 11 '15 at 17:28
$begingroup$
please clarify the domain of function argument
$endgroup$
– pointguard0
Aug 4 '18 at 13:18
$begingroup$
please clarify the domain of function argument
$endgroup$
– pointguard0
Aug 4 '18 at 13:18
add a comment |
2 Answers
2
active
oldest
votes
$begingroup$
I will suppose $f(x)$ should be $f(y)$ and $f(z)$ and that we are working in $mathbb{R}$.
This is a rational expression. The only restriction is that the denominator is not $0$. Since
$$2y^2+1=0$$
has no solution then the denominator does not impose any restriction on the domain. Hence $dom(f)=mathbb{R}$.Same thinking leads to
$$z-2ne 0 Leftrightarrow zne 2.$$
The domain is $mathbb{R}backslash{2}$.
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$begingroup$
function argument could be complex.
$endgroup$
– pointguard0
Aug 4 '18 at 13:04
add a comment |
$begingroup$
The second function does not contain $z=2$ in the domain, but it can be extended continuously at this point, thus defined continuous, so the maximal domain would be all real numbers.
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add a comment |
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2 Answers
2
active
oldest
votes
2 Answers
2
active
oldest
votes
active
oldest
votes
active
oldest
votes
$begingroup$
I will suppose $f(x)$ should be $f(y)$ and $f(z)$ and that we are working in $mathbb{R}$.
This is a rational expression. The only restriction is that the denominator is not $0$. Since
$$2y^2+1=0$$
has no solution then the denominator does not impose any restriction on the domain. Hence $dom(f)=mathbb{R}$.Same thinking leads to
$$z-2ne 0 Leftrightarrow zne 2.$$
The domain is $mathbb{R}backslash{2}$.
$endgroup$
$begingroup$
function argument could be complex.
$endgroup$
– pointguard0
Aug 4 '18 at 13:04
add a comment |
$begingroup$
I will suppose $f(x)$ should be $f(y)$ and $f(z)$ and that we are working in $mathbb{R}$.
This is a rational expression. The only restriction is that the denominator is not $0$. Since
$$2y^2+1=0$$
has no solution then the denominator does not impose any restriction on the domain. Hence $dom(f)=mathbb{R}$.Same thinking leads to
$$z-2ne 0 Leftrightarrow zne 2.$$
The domain is $mathbb{R}backslash{2}$.
$endgroup$
$begingroup$
function argument could be complex.
$endgroup$
– pointguard0
Aug 4 '18 at 13:04
add a comment |
$begingroup$
I will suppose $f(x)$ should be $f(y)$ and $f(z)$ and that we are working in $mathbb{R}$.
This is a rational expression. The only restriction is that the denominator is not $0$. Since
$$2y^2+1=0$$
has no solution then the denominator does not impose any restriction on the domain. Hence $dom(f)=mathbb{R}$.Same thinking leads to
$$z-2ne 0 Leftrightarrow zne 2.$$
The domain is $mathbb{R}backslash{2}$.
$endgroup$
I will suppose $f(x)$ should be $f(y)$ and $f(z)$ and that we are working in $mathbb{R}$.
This is a rational expression. The only restriction is that the denominator is not $0$. Since
$$2y^2+1=0$$
has no solution then the denominator does not impose any restriction on the domain. Hence $dom(f)=mathbb{R}$.Same thinking leads to
$$z-2ne 0 Leftrightarrow zne 2.$$
The domain is $mathbb{R}backslash{2}$.
answered Oct 11 '15 at 22:22
Jean-François GagnonJean-François Gagnon
897315
897315
$begingroup$
function argument could be complex.
$endgroup$
– pointguard0
Aug 4 '18 at 13:04
add a comment |
$begingroup$
function argument could be complex.
$endgroup$
– pointguard0
Aug 4 '18 at 13:04
$begingroup$
function argument could be complex.
$endgroup$
– pointguard0
Aug 4 '18 at 13:04
$begingroup$
function argument could be complex.
$endgroup$
– pointguard0
Aug 4 '18 at 13:04
add a comment |
$begingroup$
The second function does not contain $z=2$ in the domain, but it can be extended continuously at this point, thus defined continuous, so the maximal domain would be all real numbers.
$endgroup$
add a comment |
$begingroup$
The second function does not contain $z=2$ in the domain, but it can be extended continuously at this point, thus defined continuous, so the maximal domain would be all real numbers.
$endgroup$
add a comment |
$begingroup$
The second function does not contain $z=2$ in the domain, but it can be extended continuously at this point, thus defined continuous, so the maximal domain would be all real numbers.
$endgroup$
The second function does not contain $z=2$ in the domain, but it can be extended continuously at this point, thus defined continuous, so the maximal domain would be all real numbers.
answered Oct 11 '15 at 23:47
user279325user279325
17416
17416
add a comment |
add a comment |
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$begingroup$
I guess $f$ should be dependant on $y$ and $z$, not on $x$? Considering finding the domain: The domain of $f$ is the set of arguments for which $f$ is well-defined. So you need to ask yourself "when is $frac{a}{b}$ not well-defined?".
$endgroup$
– Piwi
Oct 11 '15 at 17:28
$begingroup$
please clarify the domain of function argument
$endgroup$
– pointguard0
Aug 4 '18 at 13:18