UoM Maths Thread

[LOLs99]

Guys. Need a bit of help with maths!

1.Sketch and describe z=i x conj(z) in a complex plane.

[lzxnl]

Guys. Need a bit of help with maths!

1.Sketch and describe z=i x conj(z) in a complex plane.

Conj z = x-yi
Multiply by I and we get xi + y = x + yi
Equating real and imaginary parts
x = y
Or, we have the line Re (z) = Im (z)

[LOLs99]

z=x+yi
conj(z)=x-yi
z=i(x-yi)
=ix-yi^2
=y+xi

This complex number is a reflection of z=x+yi about the line Re(z)=Im(z)

Hmmh firstly thank you!!
Would z=x+yi be a straight line crossing through (0,0) when x=0 y=0?
I start with x+yi=i(x-yi) ===> x-y= i(x-y) then not sure how to interpret

Conj z = x-yi
Multiply by I and we get xi + y = x + yi
Equating real and imaginary parts
x = y
Or, we have the line Re (z) = Im (z)

Thanks! I kinda get it now. so x=y and y=x. But I started with x+yi=i(x-yi) ===> x-y= i(x-y) so not sure how to interpret that equation. can I just cancel x-y then i=1(sounds weird)?

[nhmn0301]

Hmmh firstly thank you!!
Would z=x+yi be a straight line crossing through (0,0) when x=0 y=0?
I start with x+yi=i(x-yi) ===> x-y= i(x-y) then not sure how to interpret
Thanks! I kinda get it now. so x=y and y=x. But I started with x+yi=i(x-yi) ===> x-y= i(x-y) so not sure how to interpret that equation. can I just cancel x-y then i=1(sounds weird)?

x+iy = i(x-iy)
x + iy  = xi + y  ( i^2 = -1 )
hence, group real and imaginary,
( x- y ) + ( x - y)i = 0 + 0i
x-y = 0      x-y=0
x= y          x=y

[LOLs99]

x+iy = i(x-iy)
x + iy  = xi + y  ( i^2 = -1 )
hence, group real and imaginary,

x-y = 0      x-y=0
x= y          x=y

Ohhh right!!!"( x- y ) + ( x - y)i = 0 + 0i"- That was what I didn't think of !
Thanks 

[scribble]

HOWS AM GUYS ARE YOU ALL HAVING ALL THE FUN IN THE WORLD?

[user2357]

Anyone interested in a MAST10008 study group?   

[user2357]

HOWS AM GUYS ARE YOU ALL HAVING ALL THE FUN IN THE WORLD?

I was gonna do calculus 2 then changed my mind and now doing AM1
I looked through the exercise booklet and some of the proving questions look scary...

[lzxnl]

You'll get to doing those, don't worry about them now.

Like, at least get the online assignment done first

[Ballerina]

Trololo I joined the Melbourne University Mathematics Society for their free BBQs, and the only math classes I do are psychology classes which are technically classified as 'quantitative' by UoM alongside chem and math. Even though psychology isn't even classified as a science (it's charged as arts). Psych is math but not science yeah okay absolutely UoM


who want discuss brain

[alchemy]

Trololo I joined the Melbourne University Mathematics Society for their free BBQs

It would've been funnier if you had said: "I joined the MUM Society..."  LOL 

[Ballerina]

It would've been funnier if you had said: "I joined the MUM Society..."  LOL 

It is true that I see no  purpose to mums outside of free food <3

[Deleted User]

Been a while since I last did probability, so could someone help me out with two really easy questions?

So I know what the proper mathematical definitions for mutually exclusive events [P(AnB)=0] and independent events [P(AnB)=P(A)*P(B)], but I'm trying to get my head around what the practical definitions are.

So am I right in saying that:

1) Mutually exclusive events are events of the same "type," and that they have to occur simultaneously, such that they can be represented in a Venn diagram?

2) Independent events are events of different type, and that one event has to occur before the other, such that they can be represented in a tree diagram?

[Oilerian]

Been a while since I last did probability, so could someone help me out with two really easy questions?

So I know what the proper mathematical definitions for mutually exclusive events [P(AnB)=0] and independent events [P(AnB)=P(A)*P(B)], but I'm trying to get my head around what the practical definitions are.

So am I right in saying that:

1) Mutually exclusive events are events of the same "type," and that they have to occur simultaneously, such that they can be represented in a Venn diagram?

2) Independent events are events of different type, and that one event has to occur before the other, such that they can be represented in a tree diagram?

Well for 1) or MEEs, the straightforward explanation is by looking at the definition, MEE are events that cannot happen at the same instance. The venn diagram would be two separate circles. The concrete example is tossing coins, sleep/wake, you cannot have both tails and head at the same time, nor can you sleep and wake up at the same time.

2) They are events which have independent probability of happening. Examples help a lot. http://www.mathgoodies.com/lessons/vol6/independent_events.html

[notveryasian]

anyone's grades not registering for AM1? says i got 0 but im sure i did the online assignment and submitted correctly