#1
The complex number: a is given that:
a = 2((cos(pi/8) +sin(pi/8))

on your diagram, draw and label:
(z - a) = 6

the locus of points:
arg(z - a) = (5pi)/8

the first locus is just a circle, centre at z, with radius 6, right?

Need help, espeically with the last bit. Is the last question a shaded regiion in and around the line from the origin to complex number a that stretches on forever? which is 5pi/6 distance away from the line than goes trough a and onwards, and since it's 5pi/8 distance away from every point on that infinitely long line it's really just a shaded region? if that made sense. help please lol.
0
10 years ago
#2
Ermm... z is the variable so it should be a circle, centre a

arg(z-a) is the angle between and the origin. You need to make that angle . Therefore it will be a half line (I'll leave you to figure out where and at what angle)

Also is ?
0
#3
yeah, it is
0
#4
Still a bit confused. Is it, centre A, a circle that goes from arga to 5pi/8, so it's not a full circle, but one that goes to that angle then stops?
0
10 years ago
#5
(Original post by Tallon)
Still a bit confused. Is it, centre A, a circle that goes from arga to 5pi/8, so it's not a full circle, but one that goes to that angle then stops?

The locus of z is a circle centre a radius 6.

This is because z-a is the line from a to z and the modulus signs indicate that the length of this line is 6.

The second part is a completely separate question
0
10 years ago
#6
Tallon,

If you want to understand the circle centre, consider this:

This is the circle centre radius .
0
10 years ago
#7
Mr M, a is not a real number. He made a mistake in the first post
0
10 years ago
#8
(Original post by SimonM)
Mr M, a is not a real number. He made a mistake in the first post
I wondered why he was finding it difficult.

My earlier post is now corrected in the light of this information.
0
#9
I know the second part is a completely seperate question. that's the bit I'm stuck on lol
0
10 years ago
#10
(Original post by Tallon)
I know the second part is a completely seperate question. that's the bit I'm stuck on lol
Private message me with an email address and I will send you a Powerpoint that will illuminate the matter for you.
0
X

new posts

Latest
My Feed

### Oops, nobody has postedin the last few hours.

Why not re-start the conversation?

see more

### See more of what you like onThe Student Room

You can personalise what you see on TSR. Tell us a little about yourself to get started.

### University open days

• University of the Arts London
MA Performance Design and Practice Open Day Postgraduate
Thu, 24 Jan '19
• Brunel University London
Sat, 26 Jan '19
• SOAS University of London
Sat, 26 Jan '19

### Poll

Join the discussion

#### Are you chained to your phone?

Yes (61)
20%
Yes, but I'm trying to cut back (120)
39.34%
Nope, not that interesting (124)
40.66%