Turn on thread page Beta
 You are Here: Home >< Maths

complex numbers p4 watch

1. (Original post by lgs98jonee)
wot does arg mean?
Argument, the angle that the line to a point on an Argand diagram makes with the +ve real axis. I think the principal argument, Arg z is defined to be between -π and π.
2. (Original post by lgs98jonee)
wot does arg mean?
its the argument
its angle from origin to the complex number in vector form. from pi to - pi
3. can someone gimme a hand with q8 on ex 3d in the p4 book? thanks.
4. (Original post by kikzen)
can someone gimme a hand with q8 on ex 3d in the p4 book? thanks.
Couldn't type it up could you? I don't have the text book
5. (Original post by Bezza)
Couldn't type it up could you? I don't have the text book
1/(x+iy) + 1/(1+2i) = 1

x and y are real, find x and y.
6. (Original post by kikzen)
1/(x+iy) + 1/(1+2i) = 1

x and y are real, find x and y.
[(1 + 2i) + (x + iy)]/(x + iy)(1 + 2i) = 1

(1 + 2i) + (x + iy) = (x + iy)(1 + 2i)

Multiply out the RHS and compare real and imaginary parts. I think.
7. (Original post by Nylex)
[(1 + 2i) + (x + iy)]/(x + iy)(1 + 2i) = 1

(1 + 2i) + (x + iy) = (x + iy)(1 + 2i)

Multiply out the RHS and compare real and imaginary parts. I think.
the bounds of my stupidity know no limits.

danke.
8. (Original post by kikzen)
1/(x+iy) + 1/(1+2i) = 1

x and y are real, find x and y.
Multiply by (x+yi)(1+2i):

1 + 2i + x + yi = (x+yi)(1+2i)
1 + 2i + x + yi = x + 2xi + yi - 2y
1 + 2i = 2xi - 2y
(xi - y) = ((1/2) + i)

Compare real parts:

-y = 1/2
y = -1/2

Im parts:

x = 1

I think...
9. (Original post by kikzen)
the bounds of my stupidity know no limits.

danke.
Np. Does it work though?
10. (Original post by kikzen)
1/(x+iy) + 1/(1+2i) = 1

x and y are real, find x and y.
1/(x+iy) = 1-1/(1+2i) = 2i/(1+2i)
(x+iy) = (1+2i) /2i= 1/(2i)+1=1 - i/2
so x=1 and y=-1/2
11. yes it works

Turn on thread page Beta
TSR Support Team

We have a brilliant team of more than 60 Support Team members looking after discussions on The Student Room, helping to make it a fun, safe and useful place to hang out.

This forum is supported by:
Updated: June 26, 2004
Today on TSR

Are you living on a tight budget at uni?

From budgets to cutbacks...

University open days

1. University of Cambridge
Wed, 26 Sep '18
2. Norwich University of the Arts
Fri, 28 Sep '18
3. Edge Hill University
Faculty of Health and Social Care Undergraduate
Sat, 29 Sep '18
Poll
Useful resources

Make your revision easier

Maths Forum posting guidelines

Not sure where to post? Read the updated guidelines here

How to use LaTex

Writing equations the easy way

Study habits of A* students

Top tips from students who have already aced their exams

Create your own Study Planner

Never miss a deadline again

Thinking about a maths degree?

Chat with other maths applicants

Can you help? Study help unanswered threads

Groups associated with this forum:

View associated groups

The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.

Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE