First year Math help (1 Viewer)

[melimoo]

ok
both MATH1001 and MATH1002 are hard. and make me want to cry a little bit.

now if any smart 1st years or experienced and knowledgable other-years want to help me i might love you for some time.

ok now in the attached pdf:
Q1 c)
and
Q2
i can't do. you don't have to tell me the answers to the exact questions, but some guidance in graphing complex numbers of that kind would be helpful, as would any alternate method to doing Q2 that won't keep giving me and answer of -1 for the first part!!!
argh

ps. where do i even FIND the MATH1002 assignment.

yours faithfully
melimoo <3

 

[LostAuzzie]

I can't seem to open the file there, but if it's the 1st assignment for 1001 then:
Q1c for part one try using z=a + ib and work from there, theres a number of examples in the lecture notes similar to part two and for part three just combine the two
As for Q2 I'm having trouble with that myself

And also theres a MATH1002 Assignment

 

[melimoo]

the file should work
and ive looked through the lecture notes for Q1c) but i don't even know how to read it. is it like "the real part of the complex number (1 + i) is greater than -2"?
mainly i just don't get this part: (1 + i)z >>>>what does that mean. waaah

and Q2. ive tried the de moivre's theorum with arg z = 0, +2pi, -2pi, .... but i keep getting -1 x cis = -1 x 1 = -1
rargh.

oh and ps. i am under the impression we have a math1002 assignment due on friday. ill double check my dates... :S

 

[melimoo]

ok
my bad. i dont know where i got the crazy idea that we have a math1002 assignment due this friday.its due on the 26th of april. haha
now the maths faculty will think i'm a gimp
i wish i could retract emails

 

[LoneShadow]

hahaha:rofl:

 

[LostAuzzie]

the file should work
and ive looked through the lecture notes for Q1c) but i don't even know how to read it. is it like "the real part of the complex number (1 + i) is greater than -2"?
mainly i just don't get this part: (1 + i)z >>>>what does that mean. waaah

and Q2. ive tried the de moivre's theorum with arg z = 0, +2pi, -2pi, .... but i keep getting -1 x cis = -1 x 1 = -1
rargh.

oh and ps. i am under the impression we have a math1002 assignment due on friday. ill double check my dates... :S

Page 16 has examples like part 2
for part 1, let z = a + ib then multiply by (1 + i)

And my problem with question 2 is im NOT getting -1 as a fifth root of -1 which it should be

 

[melimoo]

ooh ok. i'll try that for Q1 thanks

and i can tell you how to get the 5th root to be -1, but arent there meant to be many different roots containing complex numbers and the like?

 

[LostAuzzie]

yer but one of them should still be -1, I keep getting +1 instead

 

[melimoo]

how do i get the others?

omg. i am such an idiot. no i did not get -1 as an answer. due to the fact that r = 1 and NOT -1

grrrrrr im really quite dim

 

[LostAuzzie]

using the +2kpi/n part, anyways -1 should be a solution though

 

[sydneyphoenix]

For those who are doing MATH1901, how much of the assignment have you done?
I've done all of Q1, though part b seems quite dodgy, and think I've got Q2.
But Q3a) seems quite screwed, not quite sure how to reason this function z maps a circle of radius 2 from origin. Oh well, I will figure it out.

 

[AntiHyper]

for part 1, let z = a + ib then multiply by (1 + i)

hmm okay i did that and i ended up with:
Re( (a-b) + (a+b)i ) > -2
(a-b) > -2
wtf is a & wtf is b

 

[Templar]

Let a=x and b=y. Now plot.

 

[LoneShadow]

Let a=x and b=y. Now plot.

lol. 2 varibles reduced to another 2. hehehe

 

[AntiHyper]

Let a=x and b=y. Now plot.

Ah ok thanks
so i get the graph to be a dotted straight line & shading same as "y < x + 2"

 

[melimoo]

hahaha:rofl:

lol. 2 varibles reduced to another 2. hehehe

dude. if you can't post anything helpful, constructive or at least witty, get the fuck out of my thread
kthx

 

[Zeppelin]

First year maths is really quite easy. Linear Algebra becomes very simple after you learn the basic techniques and use EROs. Diff Calc is tougher, but with study it's not too bad. I know it's easy for a second year student to say this, but hang in there! I felt exactly the same way when I started last year.

Now MATH2061 - that's freakin' hard.

 

[melimoo]

ok. question. don't know how to approach from MATH1002

if i'm given 2 points, say, P(x,y,z) and Q (X,Y,Z) and i want to find the line through them, i assume i use the formula (if wanting parametric vector eqn)
r = ro +tv

now do i take P to be ro and Q to be r, or do i make Q into the parallel vector v ?????? can i even plug in Q(X,Y,Z) to get v? i don't think thats right..... HELP

also,

how about orders of operations concerning dot and cross products?

like say i had a . b x c ? (yes, from asst )

 

[LoneShadow]

ok. question. don't know how to approach from MATH1002

if i'm given 2 points, say, P(x,y,z) and Q (X,Y,Z) and i want to find the line through them, i assume i use the formula (if wanting parametric vector eqn)
r = ro +tv

now do i take P to be ro and Q to be r, or do i make Q into the parallel vector v ?????? can i even plug in Q(X,Y,Z) to get v? i don't think thats right..... HELP

also,

how about orders of operations concerning dot and cross products?

like say i had a . b x c ? (yes, from asst )

If you have not been given the vector v, just find the vector PQ = (X-x)i+(Y-y)j+(Z-z)k. and let v equal to this vector. This works because vector v is any vector parallel to PQ. [of course PQ is parallel to itself] You can choose ro=(x,y,z) = xi+yj+zk. ro is usually the first point they give you.

Edited:
*hope no one else read it*

 

[SeDaTeD]

You have to do the cross product first because if you did the dot product first, you'll be crossing a scalar with a vector, which doesn't work.