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## #76 2012-01-24 10:01:32

anonimnystefy
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### Re: Oh,Oh,Oh,merry analysis!!!

hi JEF

no no.it's something we've done last year.

hi bobbym

well it would be nice.

The limit operator is just an excuse for doing something you know you can't.
“It's the subject that nobody knows anything about that we can all talk about!” ― Richard Feynman
“Taking a new step, uttering a new word, is what people fear most.” ― Fyodor Dostoyevsky, Crime and Punishment

## #77 2012-01-24 10:07:37

bobbym

Online

### Re: Oh,Oh,Oh,merry analysis!!!

HI;

Prove that n^3+20n -10 is not O(n^2).

In mathematics, you don't understand things. You just get used to them.
I have the result, but I do not yet know how to get it.
All physicists, and a good many quite respectable mathematicians are contemptuous about proof.

## #78 2012-01-24 10:12:25

anonimnystefy
Real Member

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### Re: Oh,Oh,Oh,merry analysis!!!

hi

so n^3+20n-10>c*n^2 for any finite real number c>0.so n^3+20n-10 is w(n^2) and W(n^2) if i'm not mistaken.

i think that's enough for today.just tell me if i got this one right.

The limit operator is just an excuse for doing something you know you can't.
“It's the subject that nobody knows anything about that we can all talk about!” ― Richard Feynman
“Taking a new step, uttering a new word, is what people fear most.” ― Fyodor Dostoyevsky, Crime and Punishment

## #79 2012-01-24 10:20:39

bobbym

Online

### Re: Oh,Oh,Oh,merry analysis!!!

I do not remember about little w and Big W. But you are correct in the question.

In mathematics, you don't understand things. You just get used to them.
I have the result, but I do not yet know how to get it.
All physicists, and a good many quite respectable mathematicians are contemptuous about proof.

## #80 2012-01-24 20:12:13

anonimnystefy
Real Member

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### Re: Oh,Oh,Oh,merry analysis!!!

hi bobbym

next?

The limit operator is just an excuse for doing something you know you can't.
“It's the subject that nobody knows anything about that we can all talk about!” ― Richard Feynman
“Taking a new step, uttering a new word, is what people fear most.” ― Fyodor Dostoyevsky, Crime and Punishment

## #81 2012-01-25 00:16:48

bobbym

Online

### Re: Oh,Oh,Oh,merry analysis!!!

Describe the growth of

In mathematics, you don't understand things. You just get used to them.
I have the result, but I do not yet know how to get it.
All physicists, and a good many quite respectable mathematicians are contemptuous about proof.

## #82 2012-01-25 10:47:03

bobbym

Online

### Re: Oh,Oh,Oh,merry analysis!!!

Hi anonimnystefy;

You have two questions for you to work on.

What does O(1) really mean? Put your answer in terms of a physical problem, something computer related.

In mathematics, you don't understand things. You just get used to them.
I have the result, but I do not yet know how to get it.
All physicists, and a good many quite respectable mathematicians are contemptuous about proof.

## #83 2012-01-25 20:33:35

anonimnystefy
Real Member

Offline

### Re: Oh,Oh,Oh,merry analysis!!!

hi bobbym

1.n/((n+1)/2) is O(1)

2.O(1) means that an application with this complexity means that for any input it will take the same time to execute.e.g. the finding of the first element in an array has complexity of (1).

The limit operator is just an excuse for doing something you know you can't.
“It's the subject that nobody knows anything about that we can all talk about!” ― Richard Feynman
“Taking a new step, uttering a new word, is what people fear most.” ― Fyodor Dostoyevsky, Crime and Punishment

## #84 2012-01-26 00:12:43

bobbym

Online

### Re: Oh,Oh,Oh,merry analysis!!!

Correct!

What is the Big(O) of this loop structure;

int x
for(x = 1; x<n; x*=2)
{
cout<< "hello";
}

In mathematics, you don't understand things. You just get used to them.
I have the result, but I do not yet know how to get it.
All physicists, and a good many quite respectable mathematicians are contemptuous about proof.

## #85 2012-01-26 05:20:08

bobbym

Online

### Re: Oh,Oh,Oh,merry analysis!!!

Hi anonimnystefy;

What does O(2^n) mean in cumputerese? Would you recommend an algorithm that had this amount of complexity?

In mathematics, you don't understand things. You just get used to them.
I have the result, but I do not yet know how to get it.
All physicists, and a good many quite respectable mathematicians are contemptuous about proof.

## #86 2012-01-26 07:04:30

anonimnystefy
Real Member

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### Re: Oh,Oh,Oh,merry analysis!!!

hi bobbym

1.it's O(log n)
2.well it's time doubles when we add one more element.time grow very very quickly,so i would never recommend it.

unfortunately i cannot think of any algorithms that are O(2^n)

The limit operator is just an excuse for doing something you know you can't.
“It's the subject that nobody knows anything about that we can all talk about!” ― Richard Feynman
“Taking a new step, uttering a new word, is what people fear most.” ― Fyodor Dostoyevsky, Crime and Punishment

## #87 2012-01-26 07:07:36

bobbym

Online

### Re: Oh,Oh,Oh,merry analysis!!!

Hi;

Very good!

You probably have never seen an O(2^n) algorithm.

In mathematics, you don't understand things. You just get used to them.
I have the result, but I do not yet know how to get it.
All physicists, and a good many quite respectable mathematicians are contemptuous about proof.

## #88 2012-01-26 07:11:30

anonimnystefy
Real Member

Offline

### Re: Oh,Oh,Oh,merry analysis!!!

probably.you?

next?

The limit operator is just an excuse for doing something you know you can't.
“It's the subject that nobody knows anything about that we can all talk about!” ― Richard Feynman
“Taking a new step, uttering a new word, is what people fear most.” ― Fyodor Dostoyevsky, Crime and Punishment

## #89 2012-01-26 07:13:02

bobbym

Online

### Re: Oh,Oh,Oh,merry analysis!!!

When we say O(log(n)), clarify.

In mathematics, you don't understand things. You just get used to them.
I have the result, but I do not yet know how to get it.
All physicists, and a good many quite respectable mathematicians are contemptuous about proof.

## #90 2012-01-26 07:25:56

anonimnystefy
Real Member

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### Re: Oh,Oh,Oh,merry analysis!!!

it means that the algorithm execution time grow slower than a linear algorithm.for example if we have 1 element the execution time will be 1,if we have 2 then it's 2,but for 3 it's also 2,for 4 it would be 3,and so on.

example algorithm is binary search algorithm.

The limit operator is just an excuse for doing something you know you can't.
“It's the subject that nobody knows anything about that we can all talk about!” ― Richard Feynman
“Taking a new step, uttering a new word, is what people fear most.” ― Fyodor Dostoyevsky, Crime and Punishment

## #91 2012-01-26 07:26:45

bobbym

Online

### Re: Oh,Oh,Oh,merry analysis!!!

True but there is one more oddity about it. Check the notation for a clue.

In mathematics, you don't understand things. You just get used to them.
I have the result, but I do not yet know how to get it.
All physicists, and a good many quite respectable mathematicians are contemptuous about proof.

## #92 2012-01-26 07:42:54

anonimnystefy
Real Member

Offline

### Re: Oh,Oh,Oh,merry analysis!!!

well i don't know what it is.maybe it's that the base needn't be specified.

The limit operator is just an excuse for doing something you know you can't.
“It's the subject that nobody knows anything about that we can all talk about!” ― Richard Feynman
“Taking a new step, uttering a new word, is what people fear most.” ― Fyodor Dostoyevsky, Crime and Punishment

## #93 2012-01-26 07:44:01

bobbym

Online

### Re: Oh,Oh,Oh,merry analysis!!!

Hmmm! You were close. In normal mathematics log(n) means logs to the base e. Here it is in base 2.

In mathematics, you don't understand things. You just get used to them.
I have the result, but I do not yet know how to get it.
All physicists, and a good many quite respectable mathematicians are contemptuous about proof.

## #94 2012-01-26 07:52:49

TheDude
Power Member

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### Re: Oh,Oh,Oh,merry analysis!!!

Sorry to be pedantic, but when base isn't specified isn't log(n) usually base 10 and ln(n) base e?

Wrap it in bacon

## #95 2012-01-26 07:55:50

anonimnystefy
Real Member

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### Re: Oh,Oh,Oh,merry analysis!!!

hi bobbym

i don't agree.somewhere log is used to represent base 10 and ln for base e.

The limit operator is just an excuse for doing something you know you can't.
“It's the subject that nobody knows anything about that we can all talk about!” ― Richard Feynman
“Taking a new step, uttering a new word, is what people fear most.” ― Fyodor Dostoyevsky, Crime and Punishment

## #96 2012-01-26 07:59:46

bobbym

Online

### Re: Oh,Oh,Oh,merry analysis!!!

Hi TheDude and anonimnystefy;

Yes, you are correct. I use ln rather than log, but Mathematica, (Wolfram ) uses the notation log(n) for the natural logarithm. I should have been clearer in making that distinction.

In mathematics, you don't understand things. You just get used to them.
I have the result, but I do not yet know how to get it.
All physicists, and a good many quite respectable mathematicians are contemptuous about proof.

## #97 2012-01-26 08:04:57

anonimnystefy
Real Member

Offline

### Re: Oh,Oh,Oh,merry analysis!!!

it's okay.you're just used to it.

next?

The limit operator is just an excuse for doing something you know you can't.
“It's the subject that nobody knows anything about that we can all talk about!” ― Richard Feynman
“Taking a new step, uttering a new word, is what people fear most.” ― Fyodor Dostoyevsky, Crime and Punishment

## #98 2012-01-26 08:07:38

bobbym

Online

### Re: Oh,Oh,Oh,merry analysis!!!

Hold on, because I have answered this question before. If you look here

http://en.wikipedia.org/wiki/Logarithm

in notations near the top you will see that when no base is specified log(x) means the natural log ( base e ) and not the common one at least one branch of math too.

In mathematics, you don't understand things. You just get used to them.
I have the result, but I do not yet know how to get it.
All physicists, and a good many quite respectable mathematicians are contemptuous about proof.

## #99 2012-01-26 08:10:09

anonimnystefy
Real Member

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### Re: Oh,Oh,Oh,merry analysis!!!

the writer uses it like that as well and probably doesn't know about the other notation.

The limit operator is just an excuse for doing something you know you can't.
“It's the subject that nobody knows anything about that we can all talk about!” ― Richard Feynman
“Taking a new step, uttering a new word, is what people fear most.” ― Fyodor Dostoyevsky, Crime and Punishment

## #100 2012-01-26 08:13:33

bobbym

Online

### Re: Oh,Oh,Oh,merry analysis!!!

It appears that either way depending on writers and branches of math both are correct.

For the purposes of asymptotic analysis log(n) means to the base 2.

In mathematics, you don't understand things. You just get used to them.
I have the result, but I do not yet know how to get it.
All physicists, and a good many quite respectable mathematicians are contemptuous about proof.