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2016ers Chit-Chat Thread (2 Viewers)

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taziibear

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Exams already gosh, if I had an exam set in the next week I'd pee myself right then and there.
 

seanieg89

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You can't evaluate the second one by inspection or simple things alone so to speak. There's a really famous proof to it though.
Just differentiate the geometric series a few times.

Or was that what you were referring to by "famous proof"?
 

leehuan

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Just differentiate the geometric series a few times.

Or was that what you were referring to by "famous proof"?
Yes lol. Just cause it's famous doesn't mean it has to be complicated.
 

seanieg89

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Yes lol. Just cause it's famous doesn't mean it has to be complicated.
I just thought I'd ask because you said you can't evaluate the second one by "simple things alone". Surely the geometric series and knowing how to differentiate rational functions are pretty simple things!
 

leehuan

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I just thought I'd ask because you said you can't evaluate the second one by "simple things alone". Surely the geometric series and knowing how to differentiate rational functions are pretty simple things!
But the first time you see it most people would forget to combine the methods together :p
 

seanieg89

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But the first time you see it most people would forget to combine the methods together :p
Idk, some series/integrals have to be evaluated in super counterintuitive ways, but I wouldn't consider this to be one of them. It has a pretty clear visual similarity to the geometric series, and differentiation of the geometric series is used plenty of times in MX2 questions.

Eg evaluating things like the sum of k*cos(kx) from k=1 to n, am sure I have seen that lots in MX2 past papers/books.

Once you know how to do such problems with degree 1, it is surely quite logical how to attack a slightly higher exponent?
 

leehuan

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When was k.cos(kx) mentioned? I don't have any memories of this one...
 

seanieg89

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When was k.cos(kx) mentioned? I don't have any memories of this one...
Will have a look when I have time if you really want, don't have any high school books with me and don't have time to look through past papers right now.
 

StudiousStudent

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Ancient and Modern half yearly exams tomorrow :party:

On another note, I found something I wrote years ago & decided it met the criteria for an English assessment. I literally changed 1 paragraph. I submitted it, and the teacher thought it was great, but couldn't understand why I had so many grammatical errors, when ordinarily I have none... haha oops. Should have proof read. I couldn't own up, either
'But miss, can you change my 90% to 100%? because my fourteen year old self was illiterate...'
 
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