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Mathematics 19 Online
OpenStudy (dls):

Complex numbers help

OpenStudy (dls):

\[\LARGE If(1+i)(1+2i)(1+3i)...(1+n i)=a+ib\] Then..2x5x10x...(1+n^2)=?

OpenStudy (dls):

@hartnn @yrelhan4 @shubhamsrg @ParthKohli

Parth (parthkohli):

\[(1^2 + 1^2)(1^2 + 2^2)(1^2 + 3^2)\cdots(1 + n^2)\]Now because \(a^2 + b^2 = (a + bi)(a - bi)\), we have\[(1 + i)(1 - i)(1 + 2i)(1 - 2i)(1 + 3i)(1 - 3i)\cdots(1 + ni)(1 - ni)\]Because we have the thing you gave above,\[= (a + bi)\times (1 - i)(1 -2i)(1 - 3i)\cdots(1 - ni)\]

Parth (parthkohli):

Wow, maine Shivam ka question answer kar diya :')

Parth (parthkohli):

Hey, I wonder if \((1 -i)(1 - 2i)(1 - 3i)\cdots (1 - ni)\) simplifies to \(a - bi\). :-\

OpenStudy (dls):

What is the final answer is the?

Parth (parthkohli):

Oh yeah, it does simplify to \(a - bi\) lol. The final answer \((a + bi)(a - bi) = a^2 + b^2\)

OpenStudy (dls):

I didn't understand a word you wrote :P What are you trying to say?

Parth (parthkohli):

Hmm, dekho... \(2 \times 5 \times 10 \cdots (1 + n^2) = (1^2 + 1^2) \times (1^2 + 2^2)\times (1^2 + 3^2)\cdots (1^2 + n^2) \). Aur ek identity hai \(x^2 + y^2 = (x + yi)(x - yi)\). Usko har bracket ki factoring ke liye use karo.

Parth (parthkohli):

Jaise ki \(1^2 + 1^2 = (1 + 1i)(1 - 1i)\) aur \(1^2 + 2^2 = (1 + 2i)(1 - 2i)\)

OpenStudy (dls):

oh :O

Parth (parthkohli):

Toh aapke paas ye result aaya.\[(a + bi)\times\color{#C00}{(1 -i)(1 - 2i)(1 - 3i)\cdots(1 - ni)} = (a +bi)\color{#C00}{(a - bi)} = a^2 + b^2 \]

Parth (parthkohli):

Is my answer correct? :|

OpenStudy (dls):

yeah ..................................

Parth (parthkohli):

OK. ^_^

OpenStudy (dls):

i didn't get the last step you wrote o.o

Parth (parthkohli):

\[(1^2 + 1^2) \times (1^2 + 2^2 ) \cdots (1^2 + n^2) = (1 + i)(1 - i) \times (1 + 2i)(1 - 2i) \cdots \times (1 + ni)(1 - ni)\]Yahan tak clear hai?

OpenStudy (dls):

(Y)

Parth (parthkohli):

Oh bete ki, yeh toh screen ke bahar hi bhag gaya. Ab jin complex numbers mein beech mein ek PLUS SIGN hai, unko saath mein le aao, aur jin complex numbers mein beech mein MINUS SIGN hai, unko alag saath mein le aao.\[(1 + i)(1 + 2i)(1 + 3i)\cdots (1 + ni) \times (1 - i)(1 - 2i)(1 - 3i)\cdots (1 - ni)\]

Parth (parthkohli):

\[\color{#C00}{(1 + i)(1 + 2i)(1 + 3i)\cdots (1 + ni)} \times \color{blue}{(1 - i)(1 - 2i)(1 - 3i)\cdots (1 - ni)}\]Red wala toh aapke question mein diya hua hai, aur blue wala uska conjugate hai.

Parth (parthkohli):

Sab theek? ^_^

OpenStudy (dls):

(Y)

Parth (parthkohli):

Toh aaya \(\color{#C00}{(a + bi)}\color{blue}{(a - bi)}\). Use \((x + yi)(x - yi) = x^2 + y^2\). :-D

OpenStudy (dls):

<3

Parth (parthkohli):

\[\Huge \color{red}{\heartsuit ♥ \heartsuit ♥ \heartsuit }\]

OpenStudy (dls):

hmm latex :P

Parth (parthkohli):

:-)

OpenStudy (shubhamsrg):

simply both side mod lena tha! ^_^

OpenStudy (shubhamsrg):

:D

Parth (parthkohli):

Mera answer galat hai? T_T

OpenStudy (shubhamsrg):

bilkul sahi hai, kabhi galat hua hai ans? ^_^

OpenStudy (shubhamsrg):

@TPK

Parth (parthkohli):

lolol, aapka method easy hai

OpenStudy (callisto):

These are wayyyy tooooo advanced for me /-\

Parth (parthkohli):

@Callisto I smell liars! ^_^

OpenStudy (dls):

@shubhamsrg tum karke batao O.o ek step ka answer?

OpenStudy (shubhamsrg):

#benedict cumberbatch

Parth (parthkohli):

#HashtagsDontWorkOnOS #NowShowHowToGetTheAnswerWithYourMethodPleaseEXCLAMATIONMARK

OpenStudy (shubhamsrg):

just take the modulus of both sides

Parth (parthkohli):

Right side ka toh \(\sqrt{a^2 + b^2}\) hai. Left side ka...?

OpenStudy (dls):

show us plz

Parth (parthkohli):

I don't know how to work with absolute values of complex numbers. I've just started with them :-\

OpenStudy (shubhamsrg):

please kya kya hai, abhi kar deta hu! :')

OpenStudy (shubhamsrg):

sqrt(1^2 + 1^2) sqrt(1^2 + 2^2) .....sqrt(1^2 +n^2) = sqrt(a^2 +b^2) S Q U A R E B O T H S I D E S

Parth (parthkohli):

:'-) OMG

OpenStudy (shubhamsrg):

<3>

OpenStudy (shubhamsrg):

yaar @yrelhan4 nahi aya, medal kise dun? :P

Parth (parthkohli):

I'd have used that if I ever knew \(|(a + bi )(x + yi)| = |a + bi| \times |x + yi|\). DLS ko de do ^_^

OpenStudy (dls):

lol

Parth (parthkohli):

Achcha phil apne paash lakh lo! ^_^

Parth (parthkohli):

Dee ell ech, aap apna medal Choobhum ko de do! ^_^

OpenStudy (dls):

You've already chosen the best response.

OpenStudy (shubhamsrg):

mai to bas @yrelhan4 ko hi dunga! B|

Parth (parthkohli):

Mela le lo, phil Choobhum ko de do! ^_^

OpenStudy (dls):

merko smaj nahi aya usne kya bolatoNO

Parth (parthkohli):

"Undo"

OpenStudy (shubhamsrg):

nvm, I gave the medal! ;)

Parth (parthkohli):

lol

Parth (parthkohli):

Nice resolution.

Parth (parthkohli):

@DLS Next question poocho!

OpenStudy (callisto):

English please? /-\

Parth (parthkohli):

Oh. :-(

OpenStudy (shubhamsrg):

I see what do did there @DLS ;)

OpenStudy (dls):

@shubhamsrg arre @ParthKohli ek step wala method batao na

OpenStudy (shubhamsrg):

you*

Parth (parthkohli):

He has already written that method... @DLS

OpenStudy (shubhamsrg):

-_-

OpenStudy (dls):

ok

OpenStudy (dls):

SBS

Parth (parthkohli):

Aapki DP mein aapki aankh laal ho gayi hai. Lagta hai aankh ka operation karwana hoga aapko. Lagta hai isliye hi nahi dekh paaye :-)

OpenStudy (dls):

someone give me the medal too imm th eodd one here

Parth (parthkohli):

@Callisto

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