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Mathematics 8 Online
OpenStudy (anonymous):

Help !

OpenStudy (anonymous):

\[\Huge (1+ \omega^2-\omega)((1-\omega^2+\omega)=?\]

OpenStudy (anonymous):

\( 1,\omega,\omega^2\) are cube roots of unity.

OpenStudy (anonymous):

@ganeshie8 @hartnn

ganeshie8 (ganeshie8):

use : \(1 + \omega + \omega^2 = 0\)

ganeshie8 (ganeshie8):

expression becomes :- \((-2\omega)(-2\omega^2)\)

OpenStudy (anonymous):

how did you apply that property?i died to apply it

OpenStudy (anonymous):

did u open the brackets and get that?

ganeshie8 (ganeshie8):

\(\Huge (\color{red}{1+ \omega^2}-\omega)((\color{red}{1}-\omega^2+\color{red}{\omega})=?\)

ganeshie8 (ganeshie8):

substitute them

OpenStudy (anonymous):

without opening? O_O

ganeshie8 (ganeshie8):

\(\Huge (\color{red}{1+ \omega^2}-\omega)((\color{red}{1}-\omega^2+\color{red}{\omega})=?\) \(\Huge (\color{red}{-\omega}-\omega)((\color{red}{-\omega^2}-\omega^2)=?\)

ganeshie8 (ganeshie8):

clear right ?

OpenStudy (anonymous):

i opened the brackets \[\LARGE \cancel 1-\omega^2+\cancel \omega+\cancel \omega^2-\omega^4+\omega^3-\omega+\omega^3-\omega^2\] \[-2 \omega^2+2\omega^3-\omega^4-\omega\]

ganeshie8 (ganeshie8):

uve complicated it :) simplify further... u should get 4

ganeshie8 (ganeshie8):

use this : \(\omega^3 = 1\)

OpenStudy (anonymous):

\[−2ω^2+2−ω^4−ω\]

ganeshie8 (ganeshie8):

\(\large −2ω^2+2−ω^{3+1}−ω \)

OpenStudy (anonymous):

\[\[\Huge −2ω^2+2−2ω=>2(1-\omega-\omega^2)\]\]

ganeshie8 (ganeshie8):

Alright, \(\Huge 2(1-(\omega+\omega^2) )\)

OpenStudy (anonymous):

what now?

ganeshie8 (ganeshie8):

\(1+\omega + \omega^2 = 0 => \omega + \omega^2 = ?\)

OpenStudy (anonymous):

finally 4 :P

ganeshie8 (ganeshie8):

im glad we finished lol

OpenStudy (anonymous):

how was this an observation based question for you?

ganeshie8 (ganeshie8):

it was supposed to be a two line solution :)

OpenStudy (anonymous):

??

ganeshie8 (ganeshie8):

dont expand the product. stare at the given product for few secs

ganeshie8 (ganeshie8):

\(\Huge (\color{red}{1+ \omega^2}-\omega)((\color{red}{1}-\omega^2+\color{red}{\omega})=? \)

ganeshie8 (ganeshie8):

in the first factor, u can replace that red thing wid a \(-\omega\)

ganeshie8 (ganeshie8):

in the second factor, u can replace that red thing wid a \(-\omega^2\)

OpenStudy (anonymous):

oh i see thanks :O

OpenStudy (anonymous):

badiya tha

ganeshie8 (ganeshie8):

np :) happens when u study too much... we dont see simple things :o

ganeshie8 (ganeshie8):

:)

OpenStudy (anonymous):

i didn't study complex no. yet this was my 1st question on application of that property..i just knew some properties..this one,w^3=1 and so so..i was just seeing a paper so saw this,wont forget now :D

ganeshie8 (ganeshie8):

ohkie :) this video is bit weird... but it should be good enough if u starting it fresh :- http://www.youtube.com/watch?v=3CXveDizmyc

OpenStudy (anonymous):

i am not doing complex no. atm,was just trying to solve it :P no time to do it..boards over head

OpenStudy (anonymous):

cant do a new chapter now is what i meant,ill see all this in march,added to playlist :D

ganeshie8 (ganeshie8):

okay, still u should knw why \(1 + \omega + \omega^2 = 0 \) and \(\omega^3 = 1\) that short video can help u derive above two quickly... it wont take more than 10 minutes for it to make sense for u

ganeshie8 (ganeshie8):

forget it, ugh i gave the wrong link, here is the correct one :- http://www.youtube.com/watch?v=6PoKNHdfdqw

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