Question

can anyone explain to me big O notation and give an example

Answer 1

I am not sure what you are talking about

Answer 2

where did you see it?

Answer 3

lol i have a discrete math class which is a pain @zzr0ck3r

Answer 4

@zzr0ck3r Big- O Notation - determine whether f is O ( g ) and, if so, find witnesses

Answer 5

so you need to know if there is a positive real number \(\epsilon\) and a \(x_0\in \mathbb{R}\) such that \(f(x) \le \epsilon g(x)\) for all \(x>x_0\). This is about convergence time?

Answer 6

\(|f(x)| \le \epsilon |g(x)|

\)

Answer 7

to be honest with you i have no idea
if you could just further more expand on that
it would be more understandable for me if you
dont mind

Answer 8

ok so let \(f(x) = 3x\) and let \(g(x)=3x+2\) then \(f\) is \(O(g(x))\) because for all \(x>1\) we have \(f(x) \le 1* g(x)\)

Answer 9

this is a very basic example.

Answer 10

my choice of \(x>1\) was random...we could have choose any number as long as the number we multiplied \(g(x)\) by was greater than \(1\)/

Answer 11

so g(x) has to be greater than f(x) for it to be considered as a big o notation? @zzr0ck3r

Answer 12

no there is some point that for all other points afterwards, f(x) is less than (or equal) to g(x) times some positive number

Answer 13

so if f(x) <= 0.00005*g(x) for all x> 2^256 then f is Og

Answer 14

ok got it

Answer 15

so at some point f is bounded by g times some positive number

Answer 16

we don't care when, as long as its for all x after that spot

and we don't care about the number g is multiplied by as long as its positive

Answer 17

you have no idea why you are using it?

Answer 18

Are you doing something with algorithms?

Answer 19

yes

Answer 20

on computers?

Answer 21

yup

Answer 22

but its basic we're not going through computer codes yet

Answer 23

so you are talking about the time it takes the algorithm to do its thing.

Answer 24

discrete is hard but can be fun.

Answer 25

no not really were just going over some stuff in class i have a test later on today i just want to have a more of an idea about the big o notation

Answer 26

trust me im basically surviving

Answer 27

maybe look up Lipchitz continuity. It is very similar (I think)

Answer 28

can you help me with these
● a | b
● the Division algorithm
● mod
● congruence class modulo n

Answer 29

a | b
the Division algorithm
mod
congruence class modulo n

Answer 30

mod is something i already know