What is 2''?

Orikal · 2003-09-05T12:37:52

Could someone tell me what 2" means? I'd search for it, but no search engines recognize " . context: show that 2n = O (3n), but 2" does not equal big-Theta (3n) [edited by - Orikal on September 2, 2003 1:46:19 AM]

Math and Physics Programming

Started by Orikal September 01, 2003 11:59 PM

17 comments, last by Orikal 20 years, 7 months ago

Cedric

158

September 02, 2003 10:31 AM

What is big-Theta? What kind of course is this? Algorithms?

capn_midnight

1,708

September 02, 2003 03:14 PM

it could still be a typographical error. I''ve seen completely different superscripts on such things before.

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Orikal

138

Author

September 02, 2003 05:26 PM

quote:Original post by Cedric
What is big-Theta? What kind of course is this? Algorithms?

So far, the course is an extension of discrete mathematics that uses mathematical proofs and graph theory to model automata that can inerpret languages described by respective grammars. Say that ten times fast.

We''re using An Introduction to Formal Languages and Automata by Peter Linz, which is where this weird 2" thing came from. I should have asked what it meant in class this morning, but I forgot.

Big-Theta and O (big-O) are functions that compare the growth rate of two functions. Ex. 2n = O (3n) basically means that 3n will always be larger than 2n for sufficiently large values of n .

And yes, one of big-Theta''s applications is analyzing the efficiency of algorithms.

rypyr

252

September 02, 2003 05:53 PM

I think it''s a superscript ''n'' with its top lopped off...just a guess...

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Fruny

1,658

September 02, 2003 05:57 PM

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Doc

586

September 02, 2003 10:04 PM

quote:Original post by Anonymous Poster
yeah, 2" = 2 inches, 2'' = 2 foot

Along that completely out-of-context line:
2'''' may also mean 2 seconds, as in degrees-minutes-seconds.

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GaulerTheGoat

122

September 04, 2003 02:36 PM

It''s gotta be 2n. After all, it is true that

2n == O(3n)but2n != BigTheta(3n)

On the other hand it is also true if it is 211 or the second derivative of 2 (with respect to anything). We can however say that it isn''t inches or seconds of an arc because these are not real numbers!
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GameCat

292

September 05, 2003 12:04 PM

If the course is on formal languages it might be some weird string notation. All books I''ve seen use e.g. k* for k repeated 0 to n times where n is any natural number, but it''s possible your book has it''s own notation. That doesn''t make any sense given the context though, it doesn''t relate to big o or theta at all.