Question

plz , need some help :)
will fan+medal
Sketch the following sets and determine which are domains:
(a) |z − 2 + i| ≤ 1;
b) |2z + 3| > 4;
(c) Imz > 1;
(d) Im z = 1;
(e) 0 ≤ arg z ≤ π/4 (z = 0);
(f) |z − 4| ≥ |z|.

Answer 1

YOu are working complex plane right?

Answer 2

yeah, but dnt knw anything

Answer 3

and besides your questino is incomplete.. if its domain/..??

Answer 4

hmm ok ill post the whol qs

Answer 5

Sketch the following sets and determine which are domains:
(a) |z − 2 + i| ≤ 1;
b) |2z + 3| > 4;
(c) Imz > 1;
(d) Im z = 1;
(e) 0 ≤ arg z ≤ π/4 (z = 0);
(f) |z − 4| ≥ |z|.

Answer 6

i dnt knw how to graph or what does domain mean in complex plane
i missed te class XD

Answer 7

Someone's not a very good student :P

Answer 8

yeah thats me lol XD

Answer 9

I was referring to me, but okay :D

Answer 10

i got 2 warning for not going to my classes hehe

Answer 11

@terenzreignz lol
ok XD

Answer 12

besides.. don't you substitude

z = x + iy

?

Answer 13

i dnt think so its the same to complex plane XD

Answer 14

No offense, Mashy, but that's not the meaning of domain in this context.
http://en.wikipedia.org/wiki/Domain_(mathematical_analysis)

Answer 15

see this is ive got
Ans. (b), (c) are domains.

Answer 16

but dnt knw how :o

Answer 17

Magic. How did you get those answers, anyway? :P

Answer 18

ermm.. dang.. my complex math is rusty then :-/

Answer 19

there is some magic book called
"manual"
for cheating :P

Answer 20

thanks for pointing it out.. ll delete that embarrassing post immediately :-/

Answer 21

no lol ugh

Answer 22

yea no he is right.. if someone read this thread.. that post would only confuse them!!!

Answer 23

be the man , and let ur words :P

Answer 24

terrenz.. be the man.. and help him solve :P

Answer 25

lol

Answer 26

help her*

Answer 27

anyway gtg nw XD
i hope to get it somtime ltr XD

Answer 28

ty for help
@terenzreignz @Mashy

Answer 29

sorry.. for that gender mistake :P

i ll try first one

(a) |z − 2 + i| ≤ 1;
\[z = x +iy\]
\[|(x-2)+i(y+1)|\le 1\]\[(x-2)^{2} + (y+1)^2 \le 1^2 or 1\]

so now can you sketch that? on a complex plane? do you recognize that oddly familiar equation?

Answer 30

circl ?

Answer 31

bingo..
u see this is just like ordinary math, just that y axis is the imaginary axis.. (it goes like 0, i, 2i, 3i, .. ) multiples of i :D

Answer 32

oh , ic
ok ill try the rest then post them
gtg nw bye ^^

Answer 33

oki doki.. see ya!

Answer 34

Also, save yourself the trouble...
Granted that Mashy has pretty much demonstrated it, regardless...
Let me give you a hint... and a very basic and fundamental one, at that.
\[\Large |z - z_o| = k\]
ALWAYS MEANS
A circle centred around \(\large z_o\) with radius k.

Answer 35

it means uper circle ^^