The Student Room Group
Uni students - Complete our survey >>
Uni students - Complete our survey >>
Uni students - Complete our survey >>

fp2 transformations of complex numbers

https://8dedc505ac3fba908c50836f59059ccce5cd0f1e.googledrive.com/host/0B1ZiqBksUHNYdHIxUkJmdndfMlE/June%202011%20MA%20-%20FP2%20Edexcel.pdf

On this paper question 5 part c, why aren't we supposed to make z the subject and sub in w=u+iv as is the standard protocol for a question like this?

It is saying "A transformation T from the z-plane to the w-plane is given by"




For example on question 1 in this paper we are also solving a problem where we are putting the imaginary part = 0, but here they have done it the other way of putting z as the subject, why is it any different to this quesiton?
https://8dedc505ac3fba908c50836f59059ccce5cd0f1e.googledrive.com/host/0B1ZiqBksUHNYdHIxUkJmdndfMlE/June%202013%20(R)%20MA%20-%20FP2%20Edexcel.pdf


I hope I'm making sense :laugh:

would appreciate any help


@Zacken any ideas? :P
(edited 7 years ago)
Reply 1
Avatar for Zacken
Zacken
22
Original post by Katiee224
https://8dedc505ac3fba908c50836f59059ccce5cd0f1e.googledrive.com/host/0B1ZiqBksUHNYdHIxUkJmdndfMlE/June%202011%20MA%20-%20FP2%20Edexcel.pdf

On this paper question 5 part c, why aren't we supposed to make z the subject and sub in w=u+iv as is the standard protocol for a question like this?

It is saying "A transformation T from the z-plane to the w-plane is given by"


Because we want to show something about z. If we re-arrange for z and then sub in u + iv, then we'll know something about the locus of w.

In this question:

We are told that Q (in the z plane) is mapped to R (in the w plane) and we are given information about R (in the w plane) and told to find information about Q (in the z plane).

In the other question:

We are told that Q (in the z plane) is mapped to R (in the w plane) and we are given information about Q (in the z plane) and told to find information about R (in the w plane)

I've used the "Q and R" in the second question even if it's not given in the question to highlight the differences. But in the second example, Q means "points on the real axis in the z-plane" and R means "line in the w-plane".
Reply 2
Avatar for Katiee224
Katiee224
OP
11
Original post by Zacken
Because we want to show something about z. If we re-arrange for z and then sub in u + iv, then we'll know something about the locus of w.

In this question:

We are told that Q (in the z plane) is mapped to R (in the w plane) and we are given information about R (in the w plane) and told to find information about Q (in the z plane).

In the other question:

We are told that Q (in the z plane) is mapped to R (in the w plane) and we are given information about Q (in the z plane) and told to find information about R (in the w plane)

I've used the "Q and R" in the second question even if it's not given in the question to highlight the differences. But in the second example, Q means "points on the real axis in the z-plane" and R means "line in the w-plane".


Aww I thought it was something along those lines but that clarifies it for me, thank you :smile:

ps you never replied to my last pm :wink: I hope your revision's going better than mine :tongue:
Reply 3
Avatar for Zacken
Zacken
22
Original post by Katiee224
Aww I thought it was something along those lines but that clarifies it for me, thank you :smile:

ps you never replied to my last pm :wink: I hope your revision's going better than mine :tongue:


No problem. :smile:

Oh, I didn't? I'm sorry! I must have forgotten. :facepalm: It's going so-so, yours? I've pretty much just stopped all A-Level revision and I'm going all out on STEP atm so not looking forward to Physics in 6 days time... you?
Reply 4
Avatar for mhardikar
mhardikar
Hi, does anyone know how to represent the line 2x + y = 5 in the complex plane? Thanks!
Original post by mhardikar
Hi, does anyone know how to represent the line 2x + y = 5 in the complex plane? Thanks!


z=x+i(5−2x)z=x+{\bf i}(5-2x) for x∈Rx\in \mathbb{R}

This is assuming you want your y-axis as the imaginary one and the x-axis as your real line??

Quick Reply

Related discussions

Latest

Trending

Trending

Articles for you