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 Exercise 5.3 
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Joined: 15 Apr 2009, 23:40
Posts: 6
Post Exercise 5.3
I have a solution, but I don't know if it's right. Basically, the question states it doesn't want a lot of computation or trigonometry. Does anyone have a solution I can compare with? Thanks!


15 Apr 2009, 23:57
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Joined: 07 Jun 2008, 08:21
Posts: 235
Post Re: Exercise 5.3
I've got a solution somewhere that I did a while back. I'll dig it out and put it on the forum. Then you can put yours on as an alternative solution if you like. Give me a few days to find it.


16 Apr 2009, 07:39
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Joined: 07 Jun 2008, 08:21
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Post Re: Exercise 5.3
Here is my attempt at this exercise. Let me know what you think and maybe you could post your solution and we could then discuss them and come to some consensus and then publish one or even two solutions.
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RTRex5-03.pdf [208.91 KiB]
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Edit: I have now put this in the Solutions section 18/4/2009


Last edited by vasco on 18 Apr 2009, 07:17, edited 1 time in total.

16 Apr 2009, 16:34

Joined: 15 Apr 2009, 23:40
Posts: 6
Post Re: Exercise 5.3
That solution seems extensive enough. I essentially did the same thing, however, mine wasn't as complete. I honestly don't think this problem should have been listed as hard (by the little face) as it appears to be sort of obvious.


18 Apr 2009, 04:19
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Joined: 07 Jun 2008, 08:21
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Post Re: Exercise 5.3
Yes, it's not too difficult. Most textbooks use a lot of Trigonometry to come to the same conclusion, so I think Penrose wanted a solution which did not require Trigonometry but showed that the expansion and rotation are just consequences of the rules for complex multiplication.
I will add this solution to the "Solutions" part of the forum.


18 Apr 2009, 06:54
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