leehuan's All-Levels-Of-Maths SOS thread (2 Viewers)

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parad0xica

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Let's start here



Apply triangle-inequality to get







where delta is something...

Paradoxica, use your magnificent algebraic manipulation skills :p
 

leehuan

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@Drsoccerball that -1 can only be dropped for limits to infinity and we also have like some polynomial or something left.
 

Paradoxica

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Let's start here



Apply triangle-inequality to get







where delta is something...

Paradoxica, use your magnificent algebraic manipulation skills :p
That's not right. The two should be on top if you were using double angle.



And if you did the algebraic conversion, then it should be



It is only one or the other. Not both.
 

InteGrand

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To deal with the -1, use the triangle inequality as shown by parad0xica.
 

leehuan

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parad0xica

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That's not right. The two should be on top if you were using double angle.



And if you did the algebraic conversion, then it should be



It is only one or the other. Not both.
Thanks for reminding the second time. I thought I remembered my double angles...

G-d damn I keep forgetting that the triangle inequality is now an ASSUMED result at uni.

But wait you still didn't address the problem with statement A
http://www.wolframalpha.com/input/?i=1-cos(x)=2sin^2(x/2)

Though my instinct tells me that it will be negligible
Thanks. Yep, it wouldn't do much harm because we will then use triangle-inequality!
 

leehuan

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That doesn't look correct. The corollary of the triangle inequality does not state |a-b| < |a|-|b|

the closest I know of is ||x|-|y||<|x-y|

But that contradicts what you suppose.
What if I replaced that - with a + keeping in mind |-1|=1

And reverse signs everywhere else where appropriate
 
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