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Complex question

A transformation, T, maps the point P from the z plane to Q in the w plane, defined below.

w=2izz,zC,z0 \displaystyle w = \frac{2-iz}{z}, z \in \mathbb{C}, z\neq 0

a) What is the locus of the point P, if P is mapped to Q which has locus arg(w)=π3 arg(w)=\frac{ \pi }{3} .

b) Find the Cartesian equation of the circle, that the arc that represents the locus of P lies on.

c) Find the area bounded by the curve and the y axis.

Could someone just have a go and tell me what answer they got so that I can see if I'm right.
Reply 1
Anyone wanna have a go?
Reply 2
Original post by Ano123
A transformation, T, maps the point P from the z plane to Q in the w plane, defined below.

w=2izz,zC,z0 \displaystyle w = \frac{2-iz}{z}, z \in \mathbb{C}, z\neq 0

a) What is the locus of the point P, if P is mapped to Q which has locus arg(w)=π3 arg(w)=\frac{ \pi }{3} .

b) Find the Cartesian equation of the circle, that the arc that represents the locus of P lies on.

c) Find the area bounded by the curve and the y axis.

Could someone just have a go and tell me what answer they got so that I can see if I'm right.


Is it the same as last night?
circle with centre ( -√ 3, -1 ) and radius 2
Reply 4
Original post by TeeEm
Is it the same as last night?


Yeah, just added the area bit on the end.
Reply 5
Original post by the bear
circle with centre ( -√ 3, -1 ) and radius 2


And the area?
Original post by Ano123
And the area?


say please
Reply 7
Original post by Ano123
And the area?


I will have it by the end of the evening as I have a very long to do list on my desk
Reply 8
Original post by the bear
say please


I got 2π/33 2\pi/3 -\sqrt3 .
Original post by Ano123
I got 4π/63 4\pi/6 -\sqrt3 .


4π/63 4\pi/6 -\sqrt3
Reply 10
If I am going to write a solution I might as well steal it
here is my version
complex.jpg
Reply 11
Original post by the bear
4π/63 4\pi/6 -\sqrt3


How did you find the area?
Reply 12
Original post by TeeEm
If I am going to write a solution I might as well steal it
here is my version
complex.jpg


Slightly different to how I did it. I defined the arc using parametric equations (I have them in my thread yesterday) and then integrated with respect to t.
Original post by Ano123
How did you find the area?


i counted the squares

i sketched the circle. i noticed that the sector of which the y axis formed a chord had a 60 degree angle.
i minused the triangles' area from the sector. job done

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