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# P6 Transformations - urgh watch

1. Hello, all. I am stuck on excercise 2d question 7 (or 6 - that looks impossible!)

for the transformation w = 225/z

show that as z moves on the locus |z-25| = 25, w lies on the locus
|w-9| = |w|

And does anyone have a good method for doing these? There are quite a few different possibilities, but it seems as though only one specific way works at a time.
2. Also, I am stuck on question 10 - I can find w's locus, but dont know how to work out clockwise/anticlockwise speed etc
3. (Original post by Rixius)
Hello, all. I am stuck on excercise 2d question 7 (or 6 - that looks impossible!)

for the transformation w = 225/z

show that as z moves on the locus |z-25| = 25, w lies on the locus
|w-9| = |w|

And does anyone have a good method for doing these? There are quite a few different possibilities, but it seems as though only one specific way works at a time.
w = 225/z
|w| = 225/|z|
========

from
w = 225/z
w - 9 = 225/z - 9z/z
w - 9 = (225 - 9z)/z
|w-9| = 9|25 - z|/|z|
|w-9| = 9.25/|z|, using |z-25| = 25
|w-9| = 225/|z|
|w-9| = |w| as required|
=======
4. Nice! Thanks for that - I dont suppose you could help with the others i have had problems with?
5. (Original post by Rixius)
Nice! Thanks for that - I dont suppose you could help with the others i have had problems with?
I'm afraid you'll have to print them out! I don't have the book

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