2012 Year 9 &10 Mathematics Marathon (4 Viewers)

Fawun

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Re: 2012 Year 9 &10 Mathematics Marathon

Well the way I did it was:

1) Show that it works for one simple case (which is often trivial).

2) Show that by rotating the line, the two arc lengths made are equal in length. Hence each "half" of the perimeter is neither gaining or losing anything.
idgi. I hope you guys all realise that i'm slow when it comes to math.
 

enoilgam

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Re: 2012 Year 9 &10 Mathematics Marathon

idgi. I hope you guys all realise that i'm slow when it comes to math.
Dont worry, I think very very few year 10's would be able to answer this question. As I said before, you really kind of have to see it.
 
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ganji

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Re: 2012 Year 9 &10 Mathematics Marathon

there we go ;P 20120825_140953.jpg
 

ganji

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Re: 2012 Year 9 &10 Mathematics Marathon

hahaha thanks ^^ and yeah there are other ways to do it but as i like to say.. keep to stupid simple unless necessary xP
 

enoilgam

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Re: 2012 Year 9 &10 Mathematics Marathon

Question 6.jpg

I thought this was a pretty tough question - its from a Year 9 5.3 mid-semester exam.
 

Fawun

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Re: 2012 Year 9 &10 Mathematics Marathon

How the hell is that year 9 5.3 if i'm in year 10 5.3 and i can't even do it.
 

Fawun

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Re: 2012 Year 9 &10 Mathematics Marathon

Wait let me think about this.
 

enoilgam

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Re: 2012 Year 9 &10 Mathematics Marathon

How the hell is that year 9 5.3 if i'm in year 10 5.3 and i can't even do it.
Wait let me think about this.
The rest of the paper had quite a few difficult questions. To be honest, I personally thought it was a bit over the top considering the rest of the test and the year level, but maybe I have low standards. It is a very good question though.
 

Fawun

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Re: 2012 Year 9 &10 Mathematics Marathon

The rest of the paper had quite a few difficult questions. To be honest, I personally thought it was a bit over the top considering the rest of the test and the year level, but maybe I have low standards. It is a very good question though.
Wait do those petals form another circle in the rectangle? If so, I think I know it.
 

enoilgam

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Re: 2012 Year 9 &10 Mathematics Marathon

Wait do those petals form another circle in the rectangle? If so, I think I know it.
Its a square (the drawing is terrible). Also, I am pretty certain the petals dont form another circle.
 

SpiralFlex

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Re: 2012 Year 9 &10 Mathematics Marathon

You guys have learnt plane geometry right?
 

deswa1

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Re: 2012 Year 9 &10 Mathematics Marathon

I personally thought that was hard- especially for year 9 level
 

enoilgam

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Re: 2012 Year 9 &10 Mathematics Marathon

My first correct question itt will be this.

inb4idontgetit
Team BoS = confidence fawun. I am actually interested to see how you do it, because I have a feeling I did it using a stupid method. Conveniently, the school decided not to provide the answers.
 

Fawun

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Re: 2012 Year 9 &10 Mathematics Marathon

I personally thought that was hard- especially for year 9 level
This will probably be one of those questions in my exam where I go "welp, i can't do this. Next question"

But can someone tell me if i'm on the right track?

So far, i'm thinking of finding the area of all 4 circles which is 4x(pix5^2) and them minus'ing it by 100cm^2 but idk what else to do
 

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