Ask your own question, for FREE!
Mathematics 16 Online
OpenStudy (rational):

HELP ! http://prntscr.com/4fwk7o

OpenStudy (paki):

@iambatman

OpenStudy (rational):

I need to show : \[\large f(p_1*p_2) = f(p_1)*f(p_2)\]

OpenStudy (anonymous):

yeah yeah

OpenStudy (anonymous):

not p any two values

OpenStudy (anonymous):

but as u said gcd need to be 1

OpenStudy (rational):

say \(\large n = ab\) such that \(\large \gcd(a,b) = 1\)

OpenStudy (rational):

need to show \[\large f(a*b) = f(a)*f(b)\] fine ?

OpenStudy (anonymous):

\[f(p_1*p_2) = (p_1*p_2)^k=etc...\]

OpenStudy (anonymous):

so \(f(p_1 p_2)=( p_1p_2)^k=p_1^k p_2^k = f(p_1)f(p_2)\)

OpenStudy (anonymous):

BSwan <3

OpenStudy (anonymous):

<\3

OpenStudy (anonymous):

:P buttt

OpenStudy (anonymous):

WOW :(

OpenStudy (anonymous):

OpenStudy (anonymous):

http://puu.sh/aPIQS.jpg

OpenStudy (rational):

i couldnt forget the laugh when somebody here said cardiod is butt shaped :D

OpenStudy (anonymous):

Haha more like a heart no? :P

OpenStudy (anonymous):

lol buttriod :P

OpenStudy (anonymous):

>_>

OpenStudy (anonymous):

lool

OpenStudy (anonymous):

hehe , i remember that

OpenStudy (anonymous):

organic math

OpenStudy (anonymous):

It exposes your true identity! Haha.

OpenStudy (anonymous):

haha :P who cares

OpenStudy (rational):

getting back to the actual question, so that proves the multiplicative property is it ? but here gcd need not be 1 i guess it works always : (ab)^n = a^n*b^n regardless of gcd right ?

OpenStudy (anonymous):

it always work , exp properties

OpenStudy (anonymous):

^

OpenStudy (anonymous):

i like this movie songs >.<

OpenStudy (rational):

which movie songs ? next question looks similar but it maybe tough http://prntscr.com/4fwmnb

OpenStudy (anonymous):

jab we met

OpenStudy (rational):

haha hahaa haaha ahhhaaaha haha thats my fav song too ^^

OpenStudy (rational):

here is actual song https://www.youtube.com/watch?v=xdUv-CwmZPs

OpenStudy (anonymous):

im watching themovie , actully its the 100 time im watching it hehe im just inlove with it lol , songs amazing still dint reach that part i think within 30 mnts it will start in movie

OpenStudy (anonymous):

ok the question hehe

OpenStudy (rational):

what does `identically zero` mean ?

OpenStudy (anonymous):

not identically zero means \(\large g(p^k) g^{-1} (p^k)\neq 0\) or \(\large g( p^k p^{-k} )\neq 0 \) the song started

OpenStudy (rational):

ok enjoy :) we can work this afterwards, im going for lunch

OpenStudy (anonymous):

shure

OpenStudy (anonymous):

its 1-1 function let \(\large n= p_1^{k_1} p_2^{k_2} p_3^{k_3}... p_r^{k_r} \) \(\large f(n)=f( p_1^{k_1} p_2^{k_2} p_3^{k_3}... p_r^{k_r}) \\\large = f(p_1^{k_1} )f(p_2^{k_2}) f(p_3^{k_3})... f(p_r^{k_r})\\\large = g(p_1^{k_1} )g(p_2^{k_2}) g(p_3^{k_3})... g(p_r^{k_r}) \\\large = g( p_1^{k_1} p_2^{k_2} p_3^{k_3}... p_r^{k_r}) = g(n) \)

OpenStudy (anonymous):

Hence :- \(\forall n \in N , f(n)=g(n) \iff f=g \) is it correct ?

OpenStudy (rational):

looks perfect :) all it means is that if you show that two functions give same value for all prime powers, then the functions are equal. we don't need to prove them for each and every integer

OpenStudy (anonymous):

:)

OpenStudy (rational):

*valid only for multiplicative functions

OpenStudy (rational):

if the functions are NOT multiplicative, then f(p^k) = g(p^k) need not imply f=g

OpenStudy (anonymous):

what if for all p and k ?

OpenStudy (anonymous):

i cant imagin any two continues function that f(x)=g(x) for all x in domain need not imply f=g >.<

OpenStudy (rational):

what about f(6^k)

OpenStudy (rational):

if `f` is not multiplicative, you canNOT write f(6^k) = f(2^k)*f*3^k) so clearly f(2^k) = g(2^k) and f(3^k) = g(3^k) NEED not imply f(6^k) = g(6^k)

OpenStudy (anonymous):

hmm , its not my point :o

OpenStudy (rational):

then ?

OpenStudy (anonymous):

f=g , iff f(x)=g(x) for all x in domain , right ?

OpenStudy (rational):

you said something like : f(p^k) = g(p^k) means f=g even if the functions are NOT multiplicative right ?

OpenStudy (anonymous):

no , this is what i mean http://prntscr.com/4fxako like this f=g , iff f(x)=g(x) for all x in domain

OpenStudy (rational):

yes \[\large f(x) = g(x)\iff f=g\]

OpenStudy (rational):

but below is true only for multiplicative functions : \[\large f(p^k) = g(p^k) \iff f=g\]

OpenStudy (anonymous):

so since , f(n) and g(n) multiplicative , and we already given f(p^k)=g(p^k) and any number n can be represented as product of primes , hence we could show f(n)=g(n) for any n in domain , thus f=g

OpenStudy (rational):

that makes sense

Can't find your answer? Make a FREE account and ask your own questions, OR help others and earn volunteer hours!

Join our real-time social learning platform and learn together with your friends!
Can't find your answer? Make a FREE account and ask your own questions, OR help others and earn volunteer hours!

Join our real-time social learning platform and learn together with your friends!