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2009 Mathematics 2U HSC Worked Solutions (1 Viewer)

T.Goodhew

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Hi everyone,

Please find "sample solutions" to the 2009 Mathematics (2 Unit) HSC Exam at 2009mathsHSCsoln_v1.2.pdf. (Updated Solutions, all errors fixed)

I realise there is another thread offering solutions however that only shows the final answers.

Before viewing the solutions please understand:

  • The solutions are not endorsed in any way by NSW Board of Studies
  • These are only "sample solutions" there may be more than one way to correctly answer a question
If you do find any errors in the solutions, please post them here.

Cheers and Good Luck with the rest of your exams :)
Tim
 
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Scinery

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oh fml that was a depressing read

should not have read that :(
 

boxhunter91

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He missed out that drawing question on q8..
Looks like i done preety well.
 

Thecorey0

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Thanks dude. Q5cii2 seems to be wrong. The triangle is an equilaterial, and hence all sides are 2. In your working you have forgot the '2' in the -2absinc bit. The answer should be 2 + 2pi/3. It's good to know my answers are right. I can now say confidently that I got 114-115.
 

tku336

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Fuck. I wrote the answers down on my sheet, so now I know exactly how many stupid mistakes I made. 110-112, with 6 marks worth of stupid errors.

P.S. Can somebody explain why 9a) everybody multiplied the chances? Surely multiplication means AND, nor OR. You should have added 8/9 + 15/16, cubed that, then 1- that., surely.
 

Thecorey0

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Fuck. I wrote the answers down on my sheet, so now I know exactly how many stupid mistakes I made. 110-112, with 6 marks worth of stupid errors.

P.S. Can somebody explain why 9a) everybody multiplied the chances? Surely multiplication means AND, nor OR. You should have added 8/9 + 15/16, cubed that, then 1- that., surely.
Well the odds that neither of them win in any given week = 8/9*15/16 =5/6. Hence the odds that they don't win for 3 continious weeks - i.e. don't win at all = (5/6)^3. Therfore the odds of winning at least once is 1 - (5/6)^3 = 91/216.
 

tku336

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Eh. I'll get 1/2 for that anyway. Do you know what a 110-112 would align to?
 
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hmmm..i think i did better than i thought....nowhere near you guys but around 80 i think
 
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im not going to read that. ill end up comitting suicide if i do LOL.

bye sydney uni, nice dreaming of you :(
 

absorber

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I think your answer with the savings question is wrong, I got something like $129966 as opposed to your $128k; and I'm not alone.

Is it because you rounded up the payments to 179? he didn't need a full payment the last time, like .4 of a payment or something, hence shouldn't be regarded as a full payment
 

T.Goodhew

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Thanks dude. Q5cii2 seems to be wrong. The triangle is an equilaterial, and hence all sides are 2. In your working you have forgot the '2' in the -2absinc bit. The answer should be 2 + 2pi/3. It's good to know my answers are right. I can now say confidently that I got 114-115.
Absolutely correct, thanks for pointing that out! :D

*Solutions updated*
 
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T.Goodhew

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I think your answer with the savings question is wrong, I got something like $129966 as opposed to your $128k; and I'm not alone.

Is it because you rounded up the payments to 179? he didn't need a full payment the last time, like .4 of a payment or something, hence shouldn't be regarded as a full payment
This is also correct, although the answer will vary between $129965 and $129966 depending on where you have rounded in your working. At first glance, I had thought a broad brush calculation would suffice but in hindsight you are absolutely correct and the fractional monthly repayment should have been dealt with correctly.

*Solutions updated*
 
B

babypunk313

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hey, im only lookin at gettin about 90ish but in Q7,a,ii:
(u+1)(4u-1) would make 4u^2+3u-1, wouldnt it? you're meant to get 4u^2+3u+1.
i tried to do it in the test but i couldnt get past that :(
 

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