Solve recursion
$begingroup$
$a_n=n^2times a_{(n-1)}$, for $ n>0, a_0=1$
Whats the correct formula to use in this case?
I solved problem with recursion before, but they had '$+$' instead of $'times'$ so there is following formula to simply solve them:
$ar^n+bnr^n$.
Is there something similar, but for multiplication instead?
discrete-mathematics
$endgroup$
add a comment |
$begingroup$
$a_n=n^2times a_{(n-1)}$, for $ n>0, a_0=1$
Whats the correct formula to use in this case?
I solved problem with recursion before, but they had '$+$' instead of $'times'$ so there is following formula to simply solve them:
$ar^n+bnr^n$.
Is there something similar, but for multiplication instead?
discrete-mathematics
$endgroup$
1
$begingroup$
Compute the first terms for $sqrt{a_n}$.
$endgroup$
– Mindlack
Jan 26 at 23:29
add a comment |
$begingroup$
$a_n=n^2times a_{(n-1)}$, for $ n>0, a_0=1$
Whats the correct formula to use in this case?
I solved problem with recursion before, but they had '$+$' instead of $'times'$ so there is following formula to simply solve them:
$ar^n+bnr^n$.
Is there something similar, but for multiplication instead?
discrete-mathematics
$endgroup$
$a_n=n^2times a_{(n-1)}$, for $ n>0, a_0=1$
Whats the correct formula to use in this case?
I solved problem with recursion before, but they had '$+$' instead of $'times'$ so there is following formula to simply solve them:
$ar^n+bnr^n$.
Is there something similar, but for multiplication instead?
discrete-mathematics
discrete-mathematics
edited Jan 26 at 23:29
abc...
3,237738
3,237738
asked Jan 26 at 23:27
GorossoGorosso
315
315
1
$begingroup$
Compute the first terms for $sqrt{a_n}$.
$endgroup$
– Mindlack
Jan 26 at 23:29
add a comment |
1
$begingroup$
Compute the first terms for $sqrt{a_n}$.
$endgroup$
– Mindlack
Jan 26 at 23:29
1
1
$begingroup$
Compute the first terms for $sqrt{a_n}$.
$endgroup$
– Mindlack
Jan 26 at 23:29
$begingroup$
Compute the first terms for $sqrt{a_n}$.
$endgroup$
– Mindlack
Jan 26 at 23:29
add a comment |
2 Answers
2
active
oldest
votes
$begingroup$
$a_n=(n!)^2$ using induction. Try to evaluate the first few terms on your own.
$endgroup$
$begingroup$
This is the only reasonable answer, but it shows that the problem is somewhat stupid as $n!$ is defined literally like that, i.e. $n! = n cdot (n-1) cdot ldots cdot 2 cdot 1$...
$endgroup$
– Klaus
Jan 26 at 23:37
add a comment |
$begingroup$
Multiply these lines together:
begin{align}
a_n&=n^2times a_{n-1}\
a_{n-1}&=(n-1)^2times a_{n-2}\
&dots\
a_2&=2^2times a_{1}\
a_1&=1^2times a_{0}\
end{align}
After canceling, we get
$$
a_n = 1^2 cdot 2^2 cdots n^2 a_0 = (1 cdot 2 cdots n)^2 = (n!)^2
$$
$endgroup$
add a comment |
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2 Answers
2
active
oldest
votes
2 Answers
2
active
oldest
votes
active
oldest
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active
oldest
votes
$begingroup$
$a_n=(n!)^2$ using induction. Try to evaluate the first few terms on your own.
$endgroup$
$begingroup$
This is the only reasonable answer, but it shows that the problem is somewhat stupid as $n!$ is defined literally like that, i.e. $n! = n cdot (n-1) cdot ldots cdot 2 cdot 1$...
$endgroup$
– Klaus
Jan 26 at 23:37
add a comment |
$begingroup$
$a_n=(n!)^2$ using induction. Try to evaluate the first few terms on your own.
$endgroup$
$begingroup$
This is the only reasonable answer, but it shows that the problem is somewhat stupid as $n!$ is defined literally like that, i.e. $n! = n cdot (n-1) cdot ldots cdot 2 cdot 1$...
$endgroup$
– Klaus
Jan 26 at 23:37
add a comment |
$begingroup$
$a_n=(n!)^2$ using induction. Try to evaluate the first few terms on your own.
$endgroup$
$a_n=(n!)^2$ using induction. Try to evaluate the first few terms on your own.
answered Jan 26 at 23:30
abc...abc...
3,237738
3,237738
$begingroup$
This is the only reasonable answer, but it shows that the problem is somewhat stupid as $n!$ is defined literally like that, i.e. $n! = n cdot (n-1) cdot ldots cdot 2 cdot 1$...
$endgroup$
– Klaus
Jan 26 at 23:37
add a comment |
$begingroup$
This is the only reasonable answer, but it shows that the problem is somewhat stupid as $n!$ is defined literally like that, i.e. $n! = n cdot (n-1) cdot ldots cdot 2 cdot 1$...
$endgroup$
– Klaus
Jan 26 at 23:37
$begingroup$
This is the only reasonable answer, but it shows that the problem is somewhat stupid as $n!$ is defined literally like that, i.e. $n! = n cdot (n-1) cdot ldots cdot 2 cdot 1$...
$endgroup$
– Klaus
Jan 26 at 23:37
$begingroup$
This is the only reasonable answer, but it shows that the problem is somewhat stupid as $n!$ is defined literally like that, i.e. $n! = n cdot (n-1) cdot ldots cdot 2 cdot 1$...
$endgroup$
– Klaus
Jan 26 at 23:37
add a comment |
$begingroup$
Multiply these lines together:
begin{align}
a_n&=n^2times a_{n-1}\
a_{n-1}&=(n-1)^2times a_{n-2}\
&dots\
a_2&=2^2times a_{1}\
a_1&=1^2times a_{0}\
end{align}
After canceling, we get
$$
a_n = 1^2 cdot 2^2 cdots n^2 a_0 = (1 cdot 2 cdots n)^2 = (n!)^2
$$
$endgroup$
add a comment |
$begingroup$
Multiply these lines together:
begin{align}
a_n&=n^2times a_{n-1}\
a_{n-1}&=(n-1)^2times a_{n-2}\
&dots\
a_2&=2^2times a_{1}\
a_1&=1^2times a_{0}\
end{align}
After canceling, we get
$$
a_n = 1^2 cdot 2^2 cdots n^2 a_0 = (1 cdot 2 cdots n)^2 = (n!)^2
$$
$endgroup$
add a comment |
$begingroup$
Multiply these lines together:
begin{align}
a_n&=n^2times a_{n-1}\
a_{n-1}&=(n-1)^2times a_{n-2}\
&dots\
a_2&=2^2times a_{1}\
a_1&=1^2times a_{0}\
end{align}
After canceling, we get
$$
a_n = 1^2 cdot 2^2 cdots n^2 a_0 = (1 cdot 2 cdots n)^2 = (n!)^2
$$
$endgroup$
Multiply these lines together:
begin{align}
a_n&=n^2times a_{n-1}\
a_{n-1}&=(n-1)^2times a_{n-2}\
&dots\
a_2&=2^2times a_{1}\
a_1&=1^2times a_{0}\
end{align}
After canceling, we get
$$
a_n = 1^2 cdot 2^2 cdots n^2 a_0 = (1 cdot 2 cdots n)^2 = (n!)^2
$$
answered Jan 27 at 0:37
lhflhf
166k11172402
166k11172402
add a comment |
add a comment |
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1
$begingroup$
Compute the first terms for $sqrt{a_n}$.
$endgroup$
– Mindlack
Jan 26 at 23:29