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## #1 2006-01-29 04:08:01

dorez
Member
Registered: 2006-01-29
Posts: 4

### Complex Numbers

Asalam O ALikum,
Straight forward --> having problems understanding following questions....

1. If X & Y are two sets & n(X) =18,n(Y)=24, n(XUY)=40   then n(X[Intersection sign]Y)=
Answer is 2 but dont know how....

2. If x^2 +y^2 = a^2 then in terms of conjgate coordinates,____
Answers is Z.Z^_ = a^2 don't know how(meaning a __ above Z)

3. IF X=[1,4] & A=[2,4] then A' =

4. IF A[1,2] & B=(0,2) then A(Intersection Sign)B=

5. If i^2=-1, then the value of i^-4k+3

6. if a+i3b= -1+3i^2k then real part =_________

7. if x+iy=5-6i^2k, the imaginary part(y) =________

8. The expression of 3/(under-the-root->6) - (under-the-root->-12) in the form of a+ib is_________
Answer-> 1/(under-root->6) + i/under-root-3

More question relating complex numbers would be coming soon

If anyone else has a question to ask can also post here....

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## #2 2006-01-29 04:29:06

kempos
Member
Registered: 2006-01-07
Posts: 77

### Re: Complex Numbers

n(AUB)=n(A) + n(B) - n(AandB)
40 = 18+24 - n(AB)
n(AB) = 2

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## #3 2006-01-29 04:34:27

kempos
Member
Registered: 2006-01-07
Posts: 77

### Re: Complex Numbers

3. A` = [1,3] ?
4. [1,2)?
5. -i

Last edited by kempos (2006-01-29 05:13:12)

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## #4 2006-01-29 04:47:58

kempos
Member
Registered: 2006-01-07
Posts: 77

### Re: Complex Numbers

solved 8 but dont know how to put it here :-(

how to paste equation from MS word? i have saved this bloody thing as a jpg try to paste it here but it does not work :-(

Last edited by kempos (2006-01-29 05:03:13)

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## #5 2006-01-29 05:06:58

dorez
Member
Registered: 2006-01-29
Posts: 4

### Re: Complex Numbers

thanks kempos
can u also put in solution steps of 3,4,5 cause these questions are new to me....

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## #6 2006-01-29 05:10:57

kempos
Member
Registered: 2006-01-07
Posts: 77

### Re: Complex Numbers

i can't do it

do not know how to put it here :-(

5. i^(-4k+3) = i^-4k * i^3 = 1/i^4k * (-i) = 1/ i^2^2k * (-i) = 1/-1^2k * (-i) =
1/1^k *(-i) = 1*(-i) = -i

Last edited by kempos (2006-01-29 05:11:36)

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## #7 2006-01-29 05:14:05

kempos
Member
Registered: 2006-01-07
Posts: 77

### Re: Complex Numbers

what do you mean by A[0,2]?

Last edited by kempos (2006-01-29 05:14:26)

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## #8 2006-01-29 05:24:16

dorez
Member
Registered: 2006-01-29
Posts: 4

### Re: Complex Numbers

didn;t got u.....?
hmmm can u also give me solutions steps of 3 and 4 because haven't ever seen these type of questions before so ..... not sure about them.....

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## #9 2006-01-29 12:15:20

Kelp Kid
Member
Registered: 2005-12-05
Posts: 31

### Re: Complex Numbers

What on earth are you talking about?

Don't know don't care

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## #10 2006-01-29 22:04:44

dorez
Member
Registered: 2006-01-29
Posts: 4

### Re: Complex Numbers

i mean
how IF X=[1,4] & A=[2,4] then A' =3. A` =
Gives answer[1,3]
how IF A[1,2] & B0,2) then A(Intersection Sign)B=
Gives answer[1,2)

Also have another question
1. If the area of a triangle is 16, formed by the points Z, Z+iZ and iZ in a complex plane then |Z|=_____

Gives 4(Under-root-->2) how?

Last edited by dorez (2006-01-29 22:14:38)

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## #11 2006-01-30 19:16:45

Tigeree
Member
Registered: 2005-11-19
Posts: 13,883

### Re: Complex Numbers

don't bother Kelp Kid

Last edited by Tiger (2006-01-30 19:17:04)

People don't notice whether it's winter or summer when they're happy.
~ Anton Chekhov
Cheer up, emo kid.

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## #12 2006-01-30 22:13:45

kempos
Member
Registered: 2006-01-07
Posts: 77

### Re: Complex Numbers

is the question about the triangle correct? haveing some problems with it :-(

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## #13 2006-01-30 22:25:28

kempos
Member
Registered: 2006-01-07
Posts: 77

### Re: Complex Numbers

I'm getting 4sqrt2 but also imaginary numbers.

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## #14 2006-01-30 22:30:09

kempos
Member
Registered: 2006-01-07
Posts: 77

### Re: Complex Numbers

ok, got it. however difficult for me to expalin.

check:
http://regentsprep.org/Regents/mathb/3C6/absvlecomlesson.htm

not the sane problem but might help

Last edited by kempos (2006-01-30 22:30:44)

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## #15 2006-01-30 22:39:26

kempos
Member
Registered: 2006-01-07
Posts: 77

ok, here you go

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## #16 2006-01-31 10:14:20

Browniegirl32296
Member
Registered: 2006-01-31
Posts: 8

### Re: Complex Numbers

How do you get to be a full memeber? or how do you get those icons?

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## #17 2006-01-31 11:29:53

MathsIsFun
Administrator
Registered: 2005-01-21
Posts: 7,664

### Re: Complex Numbers

Hi Browniegirl ... welcome to the forum. Give people a little time to respond

You are already a member, the different grades are based on how many messages you post here.

You can upload an "avatar" by going to Profile (at top), then Personality. You must first have one on your PC, though! It can't be bigger than 60x60 pixels. Some people make their own, others find one searching the internet.

"The physicists defer only to mathematicians, and the mathematicians defer only to God ..."  - Leon M. Lederman

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