What is the limit of $lim_{xtoinfty}...
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Hi I have problem to evaluate this limit:
$$lim_{xtoinfty} sin^2{(frac{1}{n^{48}})}((n+frac{1}{n^3})^{100}-(n^{32}+n^{10}+1)^3-n^{100}).$$
I tried to use the binomial theorem and tried to subtract the n with power hundred, but I am really struggling.
I can get to something like:
$lim_{xtoinfty} sin^2{(dfrac{1}{n^{48}})}(n^{100}+sum_{i=0}^{99}binom{99}{i}n^{99-j}(dfrac{1}{n^3})^j - (n^{42}+1)^3 -n^{100})$
$lim_{xtoinfty} sin^2{(dfrac{1}{n^{48}})}(sum_{i=0}^{99}binom{99}{i}n^{99-j}(dfrac{1}{n^3})^j - (n^{42}+1)^3)$
and from here I am stucky really, I am not even sure if these steps before were somewhat helpful.
calculus limits
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add a comment |
$begingroup$
Hi I have problem to evaluate this limit:
$$lim_{xtoinfty} sin^2{(frac{1}{n^{48}})}((n+frac{1}{n^3})^{100}-(n^{32}+n^{10}+1)^3-n^{100}).$$
I tried to use the binomial theorem and tried to subtract the n with power hundred, but I am really struggling.
I can get to something like:
$lim_{xtoinfty} sin^2{(dfrac{1}{n^{48}})}(n^{100}+sum_{i=0}^{99}binom{99}{i}n^{99-j}(dfrac{1}{n^3})^j - (n^{42}+1)^3 -n^{100})$
$lim_{xtoinfty} sin^2{(dfrac{1}{n^{48}})}(sum_{i=0}^{99}binom{99}{i}n^{99-j}(dfrac{1}{n^3})^j - (n^{42}+1)^3)$
and from here I am stucky really, I am not even sure if these steps before were somewhat helpful.
calculus limits
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1
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You cannot add $n^{32}$ and $n^{10}$ to get $n^{42}$
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– Peter Foreman
Feb 1 at 20:59
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Everywhere you have $x$ it should be $n$.
$endgroup$
– symplectomorphic
Feb 1 at 21:19
add a comment |
$begingroup$
Hi I have problem to evaluate this limit:
$$lim_{xtoinfty} sin^2{(frac{1}{n^{48}})}((n+frac{1}{n^3})^{100}-(n^{32}+n^{10}+1)^3-n^{100}).$$
I tried to use the binomial theorem and tried to subtract the n with power hundred, but I am really struggling.
I can get to something like:
$lim_{xtoinfty} sin^2{(dfrac{1}{n^{48}})}(n^{100}+sum_{i=0}^{99}binom{99}{i}n^{99-j}(dfrac{1}{n^3})^j - (n^{42}+1)^3 -n^{100})$
$lim_{xtoinfty} sin^2{(dfrac{1}{n^{48}})}(sum_{i=0}^{99}binom{99}{i}n^{99-j}(dfrac{1}{n^3})^j - (n^{42}+1)^3)$
and from here I am stucky really, I am not even sure if these steps before were somewhat helpful.
calculus limits
$endgroup$
Hi I have problem to evaluate this limit:
$$lim_{xtoinfty} sin^2{(frac{1}{n^{48}})}((n+frac{1}{n^3})^{100}-(n^{32}+n^{10}+1)^3-n^{100}).$$
I tried to use the binomial theorem and tried to subtract the n with power hundred, but I am really struggling.
I can get to something like:
$lim_{xtoinfty} sin^2{(dfrac{1}{n^{48}})}(n^{100}+sum_{i=0}^{99}binom{99}{i}n^{99-j}(dfrac{1}{n^3})^j - (n^{42}+1)^3 -n^{100})$
$lim_{xtoinfty} sin^2{(dfrac{1}{n^{48}})}(sum_{i=0}^{99}binom{99}{i}n^{99-j}(dfrac{1}{n^3})^j - (n^{42}+1)^3)$
and from here I am stucky really, I am not even sure if these steps before were somewhat helpful.
calculus limits
calculus limits
edited Feb 1 at 21:09


Robert Z
101k1072145
101k1072145
asked Feb 1 at 20:51
cris14cris14
1338
1338
1
$begingroup$
You cannot add $n^{32}$ and $n^{10}$ to get $n^{42}$
$endgroup$
– Peter Foreman
Feb 1 at 20:59
$begingroup$
Everywhere you have $x$ it should be $n$.
$endgroup$
– symplectomorphic
Feb 1 at 21:19
add a comment |
1
$begingroup$
You cannot add $n^{32}$ and $n^{10}$ to get $n^{42}$
$endgroup$
– Peter Foreman
Feb 1 at 20:59
$begingroup$
Everywhere you have $x$ it should be $n$.
$endgroup$
– symplectomorphic
Feb 1 at 21:19
1
1
$begingroup$
You cannot add $n^{32}$ and $n^{10}$ to get $n^{42}$
$endgroup$
– Peter Foreman
Feb 1 at 20:59
$begingroup$
You cannot add $n^{32}$ and $n^{10}$ to get $n^{42}$
$endgroup$
– Peter Foreman
Feb 1 at 20:59
$begingroup$
Everywhere you have $x$ it should be $n$.
$endgroup$
– symplectomorphic
Feb 1 at 21:19
$begingroup$
Everywhere you have $x$ it should be $n$.
$endgroup$
– symplectomorphic
Feb 1 at 21:19
add a comment |
2 Answers
2
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oldest
votes
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Hint. Note that you need just a small part of the two expansions:
$$left(n+dfrac{1}{n^3}right)^{100}=n^{100}+100n^{96}+o(n^{96}),$$
and
$$(n^{32}+n^{10}+1)^3=n^{96}+ o(n^{96}).$$
Can you take it from here?
P.S. The binomial coefficient in your first expansion should be $binom{100}{i}$.
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add a comment |
$begingroup$
Since by Taylor expansion for $n rightarrow infty, sinleft( frac{1}{n^{48}} right) approx frac{1}{n^{48}}$, a good idea is to consider only the terms of degree greater than or equal to 96, since the others goes to 0. Hence the limit shall be
$$lim_{n rightarrow infty} sin^2 left( frac{1}{n^{48}}right)left ( left ( n + frac{1}{n^3} right)^{100} - left( n^{32} + n^{10} +1 right)^3 - n^{100} right) = \
= lim_{n rightarrow infty} frac{1}{n^{96}} left( n^{100} + {{100}choose{1}} n^{96} - n^{96} - n^{100}right) = {{100}choose{1}} - 1 $$
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2 Answers
2
active
oldest
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2 Answers
2
active
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$begingroup$
Hint. Note that you need just a small part of the two expansions:
$$left(n+dfrac{1}{n^3}right)^{100}=n^{100}+100n^{96}+o(n^{96}),$$
and
$$(n^{32}+n^{10}+1)^3=n^{96}+ o(n^{96}).$$
Can you take it from here?
P.S. The binomial coefficient in your first expansion should be $binom{100}{i}$.
$endgroup$
add a comment |
$begingroup$
Hint. Note that you need just a small part of the two expansions:
$$left(n+dfrac{1}{n^3}right)^{100}=n^{100}+100n^{96}+o(n^{96}),$$
and
$$(n^{32}+n^{10}+1)^3=n^{96}+ o(n^{96}).$$
Can you take it from here?
P.S. The binomial coefficient in your first expansion should be $binom{100}{i}$.
$endgroup$
add a comment |
$begingroup$
Hint. Note that you need just a small part of the two expansions:
$$left(n+dfrac{1}{n^3}right)^{100}=n^{100}+100n^{96}+o(n^{96}),$$
and
$$(n^{32}+n^{10}+1)^3=n^{96}+ o(n^{96}).$$
Can you take it from here?
P.S. The binomial coefficient in your first expansion should be $binom{100}{i}$.
$endgroup$
Hint. Note that you need just a small part of the two expansions:
$$left(n+dfrac{1}{n^3}right)^{100}=n^{100}+100n^{96}+o(n^{96}),$$
and
$$(n^{32}+n^{10}+1)^3=n^{96}+ o(n^{96}).$$
Can you take it from here?
P.S. The binomial coefficient in your first expansion should be $binom{100}{i}$.
answered Feb 1 at 21:00


Robert ZRobert Z
101k1072145
101k1072145
add a comment |
add a comment |
$begingroup$
Since by Taylor expansion for $n rightarrow infty, sinleft( frac{1}{n^{48}} right) approx frac{1}{n^{48}}$, a good idea is to consider only the terms of degree greater than or equal to 96, since the others goes to 0. Hence the limit shall be
$$lim_{n rightarrow infty} sin^2 left( frac{1}{n^{48}}right)left ( left ( n + frac{1}{n^3} right)^{100} - left( n^{32} + n^{10} +1 right)^3 - n^{100} right) = \
= lim_{n rightarrow infty} frac{1}{n^{96}} left( n^{100} + {{100}choose{1}} n^{96} - n^{96} - n^{100}right) = {{100}choose{1}} - 1 $$
$endgroup$
add a comment |
$begingroup$
Since by Taylor expansion for $n rightarrow infty, sinleft( frac{1}{n^{48}} right) approx frac{1}{n^{48}}$, a good idea is to consider only the terms of degree greater than or equal to 96, since the others goes to 0. Hence the limit shall be
$$lim_{n rightarrow infty} sin^2 left( frac{1}{n^{48}}right)left ( left ( n + frac{1}{n^3} right)^{100} - left( n^{32} + n^{10} +1 right)^3 - n^{100} right) = \
= lim_{n rightarrow infty} frac{1}{n^{96}} left( n^{100} + {{100}choose{1}} n^{96} - n^{96} - n^{100}right) = {{100}choose{1}} - 1 $$
$endgroup$
add a comment |
$begingroup$
Since by Taylor expansion for $n rightarrow infty, sinleft( frac{1}{n^{48}} right) approx frac{1}{n^{48}}$, a good idea is to consider only the terms of degree greater than or equal to 96, since the others goes to 0. Hence the limit shall be
$$lim_{n rightarrow infty} sin^2 left( frac{1}{n^{48}}right)left ( left ( n + frac{1}{n^3} right)^{100} - left( n^{32} + n^{10} +1 right)^3 - n^{100} right) = \
= lim_{n rightarrow infty} frac{1}{n^{96}} left( n^{100} + {{100}choose{1}} n^{96} - n^{96} - n^{100}right) = {{100}choose{1}} - 1 $$
$endgroup$
Since by Taylor expansion for $n rightarrow infty, sinleft( frac{1}{n^{48}} right) approx frac{1}{n^{48}}$, a good idea is to consider only the terms of degree greater than or equal to 96, since the others goes to 0. Hence the limit shall be
$$lim_{n rightarrow infty} sin^2 left( frac{1}{n^{48}}right)left ( left ( n + frac{1}{n^3} right)^{100} - left( n^{32} + n^{10} +1 right)^3 - n^{100} right) = \
= lim_{n rightarrow infty} frac{1}{n^{96}} left( n^{100} + {{100}choose{1}} n^{96} - n^{96} - n^{100}right) = {{100}choose{1}} - 1 $$
answered Feb 1 at 21:04


JCFJCF
356112
356112
add a comment |
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1
$begingroup$
You cannot add $n^{32}$ and $n^{10}$ to get $n^{42}$
$endgroup$
– Peter Foreman
Feb 1 at 20:59
$begingroup$
Everywhere you have $x$ it should be $n$.
$endgroup$
– symplectomorphic
Feb 1 at 21:19