Is it guaranteed that $sqrt[3]{a+sqrt{b}}$ can be denested with or without complex numbers?
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I tried to use the cubic formula before, but was always stuck at simplifying the cube root. I had learned that you can always simplify $sqrt{a+sqrt{b}}$ by solving, but can I always simplify $sqrt[3]{a+sqrt{b}}$, too, or is there a restriction?
Edit:
It can contain complex numbers, and I mean denesting by simplifying. $sqrt{a+sqrt{b}}$ is the same as solving m+n=a, and $mn={bover4}$.
Second Edit:
An example will be denesting $sqrt{1+sqrt{2}}$. $sqrt{1+sqrt{2}}$ will be $sqrt{m}+sqrt{n}$, where m+n=1, and $mn={1over2}$. Squaring the first equation then subtracting the second equation 4 times, m-n=$i$. So, $sqrt{1+sqrt{2}}$=$sqrt{1+iover2}+sqrt{1-iover2}$.
radicals nested-radicals
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add a comment |
$begingroup$
I tried to use the cubic formula before, but was always stuck at simplifying the cube root. I had learned that you can always simplify $sqrt{a+sqrt{b}}$ by solving, but can I always simplify $sqrt[3]{a+sqrt{b}}$, too, or is there a restriction?
Edit:
It can contain complex numbers, and I mean denesting by simplifying. $sqrt{a+sqrt{b}}$ is the same as solving m+n=a, and $mn={bover4}$.
Second Edit:
An example will be denesting $sqrt{1+sqrt{2}}$. $sqrt{1+sqrt{2}}$ will be $sqrt{m}+sqrt{n}$, where m+n=1, and $mn={1over2}$. Squaring the first equation then subtracting the second equation 4 times, m-n=$i$. So, $sqrt{1+sqrt{2}}$=$sqrt{1+iover2}+sqrt{1-iover2}$.
radicals nested-radicals
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I feel a bit confused about what you mean by "complex numbers". So can you please show perhaps an example of an acceptable denesting of $sqrt{1+sqrt{2}}$?
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– Edward H.
Feb 1 at 1:28
add a comment |
$begingroup$
I tried to use the cubic formula before, but was always stuck at simplifying the cube root. I had learned that you can always simplify $sqrt{a+sqrt{b}}$ by solving, but can I always simplify $sqrt[3]{a+sqrt{b}}$, too, or is there a restriction?
Edit:
It can contain complex numbers, and I mean denesting by simplifying. $sqrt{a+sqrt{b}}$ is the same as solving m+n=a, and $mn={bover4}$.
Second Edit:
An example will be denesting $sqrt{1+sqrt{2}}$. $sqrt{1+sqrt{2}}$ will be $sqrt{m}+sqrt{n}$, where m+n=1, and $mn={1over2}$. Squaring the first equation then subtracting the second equation 4 times, m-n=$i$. So, $sqrt{1+sqrt{2}}$=$sqrt{1+iover2}+sqrt{1-iover2}$.
radicals nested-radicals
$endgroup$
I tried to use the cubic formula before, but was always stuck at simplifying the cube root. I had learned that you can always simplify $sqrt{a+sqrt{b}}$ by solving, but can I always simplify $sqrt[3]{a+sqrt{b}}$, too, or is there a restriction?
Edit:
It can contain complex numbers, and I mean denesting by simplifying. $sqrt{a+sqrt{b}}$ is the same as solving m+n=a, and $mn={bover4}$.
Second Edit:
An example will be denesting $sqrt{1+sqrt{2}}$. $sqrt{1+sqrt{2}}$ will be $sqrt{m}+sqrt{n}$, where m+n=1, and $mn={1over2}$. Squaring the first equation then subtracting the second equation 4 times, m-n=$i$. So, $sqrt{1+sqrt{2}}$=$sqrt{1+iover2}+sqrt{1-iover2}$.
radicals nested-radicals
radicals nested-radicals
edited Feb 1 at 19:40
Math Lover
asked Jan 31 at 0:31
Math LoverMath Lover
17410
17410
$begingroup$
I feel a bit confused about what you mean by "complex numbers". So can you please show perhaps an example of an acceptable denesting of $sqrt{1+sqrt{2}}$?
$endgroup$
– Edward H.
Feb 1 at 1:28
add a comment |
$begingroup$
I feel a bit confused about what you mean by "complex numbers". So can you please show perhaps an example of an acceptable denesting of $sqrt{1+sqrt{2}}$?
$endgroup$
– Edward H.
Feb 1 at 1:28
$begingroup$
I feel a bit confused about what you mean by "complex numbers". So can you please show perhaps an example of an acceptable denesting of $sqrt{1+sqrt{2}}$?
$endgroup$
– Edward H.
Feb 1 at 1:28
$begingroup$
I feel a bit confused about what you mean by "complex numbers". So can you please show perhaps an example of an acceptable denesting of $sqrt{1+sqrt{2}}$?
$endgroup$
– Edward H.
Feb 1 at 1:28
add a comment |
1 Answer
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If you mean "can be simplified" as deleting of nested radicals then it's not always possible.
For example, for $sqrt{3-2sqrt2}$ we can do it, but for $sqrt{sqrt2-1}$ it's impossible.
For $sqrt[3]{5sqrt2-7}$ we can do it, but for $sqrt[3]{sqrt2-1}$ it's impossible.
For $sqrt[3]{sqrt[3]2-1}$ we can do it, but for $sqrt[3]{sqrt[3]2+1}$ it's impossible.
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1 Answer
1
active
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1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
$begingroup$
If you mean "can be simplified" as deleting of nested radicals then it's not always possible.
For example, for $sqrt{3-2sqrt2}$ we can do it, but for $sqrt{sqrt2-1}$ it's impossible.
For $sqrt[3]{5sqrt2-7}$ we can do it, but for $sqrt[3]{sqrt2-1}$ it's impossible.
For $sqrt[3]{sqrt[3]2-1}$ we can do it, but for $sqrt[3]{sqrt[3]2+1}$ it's impossible.
$endgroup$
add a comment |
$begingroup$
If you mean "can be simplified" as deleting of nested radicals then it's not always possible.
For example, for $sqrt{3-2sqrt2}$ we can do it, but for $sqrt{sqrt2-1}$ it's impossible.
For $sqrt[3]{5sqrt2-7}$ we can do it, but for $sqrt[3]{sqrt2-1}$ it's impossible.
For $sqrt[3]{sqrt[3]2-1}$ we can do it, but for $sqrt[3]{sqrt[3]2+1}$ it's impossible.
$endgroup$
add a comment |
$begingroup$
If you mean "can be simplified" as deleting of nested radicals then it's not always possible.
For example, for $sqrt{3-2sqrt2}$ we can do it, but for $sqrt{sqrt2-1}$ it's impossible.
For $sqrt[3]{5sqrt2-7}$ we can do it, but for $sqrt[3]{sqrt2-1}$ it's impossible.
For $sqrt[3]{sqrt[3]2-1}$ we can do it, but for $sqrt[3]{sqrt[3]2+1}$ it's impossible.
$endgroup$
If you mean "can be simplified" as deleting of nested radicals then it's not always possible.
For example, for $sqrt{3-2sqrt2}$ we can do it, but for $sqrt{sqrt2-1}$ it's impossible.
For $sqrt[3]{5sqrt2-7}$ we can do it, but for $sqrt[3]{sqrt2-1}$ it's impossible.
For $sqrt[3]{sqrt[3]2-1}$ we can do it, but for $sqrt[3]{sqrt[3]2+1}$ it's impossible.
answered Jan 31 at 1:03
Michael RozenbergMichael Rozenberg
110k1896201
110k1896201
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$begingroup$
I feel a bit confused about what you mean by "complex numbers". So can you please show perhaps an example of an acceptable denesting of $sqrt{1+sqrt{2}}$?
$endgroup$
– Edward H.
Feb 1 at 1:28