Carrotsticks' Solutions 2015 Extension 1 HSC (5 Viewers)

[Carrotsticks]

https://www.dropbox.com/s/nmm942epl7x58mk/HSC Extension 1 2015 Solutions.pdf?dl=0

Again, please let me know if you see any typos or calculation errors (which I am rather prone to)!

 

[invisible036]

Re: Carrotsticks' Solutions 2015 Extension 2 HSC1

cheers Carrot, q 11c i think it was -3<x<=1, cuz when x=-3 it is undefined

 

[Carrotsticks]

Re: Carrotsticks' Solutions 2015 Extension 2 HSC1

cheers Carrot, q 11c i think it was -3<x<=1, cuz when x=-3 it is undefined

RIP Carrotsticks state rank, fell for the classic trap ='(

Thank you, fixed!

 

[ENFP]

Re: Carrotsticks' Solutions 2015 Extension 2 HSC1

Question 13bi, where's the nCk?

 

[godofindolence]

Re: Carrotsticks' Solutions 2015 Extension 2 HSC1

For the binomial expansion in 13b, is there supposed to be the nCk?

 

[rand_althor]

Re: Carrotsticks' Solutions 2015 Extension 2 HSC1

Shouldn't it be 2.57 for 12(d)(iii)?

 

[hoboparkbench]

Re: Carrotsticks' Solutions 2015 Extension 2 HSC1

12)d)iii) is 2.57

 

[samcalamos]

Re: Carrotsticks' Solutions 2015 Extension 2 HSC1

using this i got 100% in all except for all of 14 c i got wrong. Dam binomials

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[Carrotsticks]

Re: Carrotsticks' Solutions 2015 Extension 2 HSC1

Have fixed the Newton's method & binomial result!

 

[Bump]

Re: Carrotsticks' Solutions 2015 Extension 2 HSC1

If I go from v^2=(x-1)^2 to v=x-1 without talking about the negative part, will I get full marks?

 

[Carrotsticks]

Re: Carrotsticks' Solutions 2015 Extension 2 HSC1

If I go from v^2=(x-1)^2 to v=x-1 without talking about the negative part, will I get full marks?

Definitely not. You would've gotten 2 out of 3.

 

[holy123123]

Re: Carrotsticks' Solutions 2015 Extension 2 HSC1

For limiting position, can I let acceleration equal zero? It gives me x = 1 as well

 

[Vizsla]

Re: Carrotsticks' Solutions 2015 Extension 2 HSC1

Could you lose a mark if you put the binomial expression in your calculator and then gave that as your answer?

 

[Carrotsticks]

Re: Carrotsticks' Solutions 2015 Extension 2 HSC1

For limiting position, can I let acceleration equal zero? It gives me x = 1 as well

Yes that also works in this particular scenario.

But it may not work always. That method assumes that the particle is either reaching constant speed or zero speed as it approaches the limiting displacement (in this case the velocity approaches zero).

If you have a particle that gets faster and faster, whilst still approaching this limiting displacement, then this method won't work anymore. I haven't done a full investigation into this scenario yet though.

 

[Carrotsticks]

Re: Carrotsticks' Solutions 2015 Extension 2 HSC1

Could you lose a mark if you put the binomial expression in your calculator and then gave that as your answer?

No, you should not lose the mark.

 

[iforgotmyname]

Re: Carrotsticks' Solutions 2015 Extension 2 HSC1

56raw rip, no band 6 Gg fk


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[Vizsla]

Re: Carrotsticks' Solutions 2015 Extension 2 HSC1

No, you should not lose the mark.

I think I got 100 then. How do they distinguish the state rankers?

 

[Drsoccerball]

Re: Carrotsticks' Solutions 2015 Extension 2 HSC1

Do extension 1 teachers understand that integrating with bounds gets rid of the plus C in the last question? Will I lose marks?

 

[Carrotsticks]

Re: Carrotsticks' Solutions 2015 Extension 2 HSC1

I think I got 100 then. How do they distinguish the state rankers?

I cannot say anything with absolute certainty.

Do extension 1 teachers understand that integrating with bounds gets rid of the plus C in the last question? Will I lose marks?

Yes, this method is very well understood by the senior HSC markers, and instructions would have been passed down to the normal markers accordingly. I was going to do the problems using this method, but I figured for the benefit of students reading my solutions (who I presume are mostly Extension 1 only students), they may be more comfortable with the +C method.

 

[Vizsla]

Re: Carrotsticks' Solutions 2015 Extension 2 HSC1

Do extension 1 teachers understand that integrating with bounds gets rid of the plus C in the last question? Will I lose marks?

Pretty sure they would