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HSC 2015 MX1 Marathon (archive) (1 Viewer)

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rand_althor

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Re: HSC 2015 3U Marathon



If anyone is unsure what the scenario looks like, here you go.
 

Drsoccerball

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Re: HSC 2015 3U Marathon

For the area question i got a very weird answer:

 

Drsoccerball

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Re: HSC 2015 3U Marathon

I think I made a mistake somewhere in my working considering that substituting k = root 2 gives my a maths error. Whats the answer?
 

rand_althor

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Re: HSC 2015 3U Marathon

The answer I have is . Note that in this scenario, the value of k is . So in your area equation, the is outside the domain of -1 to 1 for inverse sine functions. Can you explain what you did?
 

Drsoccerball

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Re: HSC 2015 3U Marathon

The answer I have is . Note that in this scenario, the value of k is . So in your area equation, the is outside the domain of -1 to 1 for inverse sine functions. Can you explain what you did?
Outer area minus inner area my integral was :
 

rand_althor

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Re: HSC 2015 3U Marathon

.
Just so that we're clear, the area you're finding is enclosed in red.
I didn't integrate to get the answer, so I'm not sure about your solution. How did you integrate ?
 

Drsoccerball

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Re: HSC 2015 3U Marathon

.
Just so that we're clear, the area you're finding is enclosed in red.
I didn't integrate to get the answer, so I'm not sure about your solution. How did you work integrate ?
let u =sinx or cosx . Also I did the with integration it should've worked :/
 

Drsoccerball

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Re: HSC 2015 3U Marathon

LOL did you just use triangle minus sector?
 

Paradoxica

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Re: HSC 2015 3U Marathon

Pardon me, but aren't the limits of integration
 
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davidgoes4wce

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Re: HSC 2015 3U Marathon

A sample of three players is to be taken from a soccer team of eleven players. How many samples are possible?

A) 11^3/3^3
B) 11!/3!
C) (11x10x9)/(3x2x1)
D) 11x10x9
 

leehuan

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Re: HSC 2015 3U Marathon

11C3 = 11!/(3!8!) = (11*10*9)/3!
as n!=n(n-1)!
 
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