2014 HSC Extension 2 Maths Carrotsticks' Solutions (1 Viewer)

[mreditor16]

guys for Q11 d) did we have to draw y=x^2 as an asymptote?

and also do you guys reckon you would lose a mark for not drawing Q12 a ) ii) as disconnected at its x-intercept, like carret seems to suggest you have to do? :O

 

[IR]

Here is a quick draft!

https://www.dropbox.com/s/dthlsed7gfknygt/HSC 2014 Extension 2 Solutions.pdf?dl=0

Sorry I had to rush through it so much, but I really have to go to class now! Please let me know if you find errors and I'll fix them when I finish teaching.

I hope you can all appreciate how much time it took to make those damn diagrams.

thanks bro.

 

[aDimitri]

the simplicity for his circle geo solution turned me on a little bit

 

[IR]

guys for Q11 d) did we have to draw y=x^2 as an asymptote?

and also do you guys reckon you would lose a mark for not drawing Q12 a ) ii) as disconnected at its x-intercept, like carret seems to suggest you have to do? :O

yes probably. How do you think now you went? /100. Just realised I got 5/10 wrong for multiple choice. And wait isnt 6) a? Now I guess with the worst case scenario probably 87/100. Best case: around 91/100

 

[RealiseNothing]

Hey guys, so carrot is off to teach his class. However he just rang me and he wants to see if anyone in this thread can finish off his proof to the conics question (the one with red writing in his solutions).

So if anyone is willing or able to find a proof using his method, please have a go and post it!

 

[esaitchkay]

thanks so much carrotsticks! really appreciate the effort

 

[aDimitri]

im expecting 93 now

 

[mreditor16]

Hey guys, so carrot is off to teach his class. However he just rang me and he wants to see if anyone in this thread can finish off his proof to the conics question (the one with red writing in his solutions).

So if anyone is willing or able to find a proof using his method, please have a go and post it!

realise, can you answer this? -

guys for Q11 d) did we have to draw y=x^2 as an asymptote? will we lose a mark for not doing so?

and also do you guys reckon you would lose a mark for not drawing Q12 a ) ii) as disconnected at its x-intercept, like carret seems to suggest you have to do? :O

 

[mreditor16]

yes probably. How do you think now you went? /100. Just realised I got 5/10 wrong for multiple choice. And wait isnt 6) a? Now I guess with the worst case scenario probably 87/100. Best case: around 91/100

will post soon on the "predict your raw mark thread"

 

[RealiseNothing]

realise, can you answer this? -

Fairly sure asymptotes like that aren't in the syllabus? I might be wrong.

 

[mirachael]

guys for Q11 d) did we have to draw y=x^2 as an asymptote?

and also do you guys reckon you would lose a mark for not drawing Q12 a ) ii) as disconnected at its x-intercept, like carret seems to suggest you have to do? :O

Theoretically, wouldn't there be a certain f(x) for which 1/f(x) would be smooth at x=-1? In that case drawing it disconnected would also be wrong in certain cases. Since they don't show any y values, its impossible to deduce which case it is, so I don't think they should penalise us.

 

[mreditor16]

Fairly sure asymptotes like that aren't in the syllabus? I might be wrong.

true true, how about the other Q?

 

[egress]

guys it is much easier than that:

Wait what???

Unless I'm tripping badly, my test paper clearly states that a≤b≤c. Your proof works perfectly fine if you fix up all of the inequality signs.

 

[mreditor16]

Theoretically, wouldn't there be a certain f(x) for which 1/f(x) would be smooth at x=-1? In that case drawing it disconnected would also be wrong in certain cases. Since they don't show any y values, its impossible to deduce which case it is, so I don't think they should penalise us.

I hope that is the case

 

[IR]

Fairly sure asymptotes like that aren't in the syllabus? I might be wrong.

I did it just incase a parabolic asymptote. Cos how would you otherwise show the curve then:?>

 

[Carrotsticks]

Am totally not texting whilst stuck in traffic right now.

Carret, for Q11 e), you said by mistake the function is odd

it is even

Oops, I think I drew it to be even anyway.

guys for Q11 d) did we have to draw y=x^2 as an asymptote?

and also do you guys reckon you would lose a mark for not drawing Q12 a ) ii) as disconnected at its x-intercept, like carret seems to suggest you have to do? :O

I doubt you do, considering that it's in question 11 too.

Also for the disconnect part, there is definitely an open circle there. Whether it connects smoothly or not, we cannot be sure. There isn't enough information to tell.

 

[mreditor16]

Wait what???

Unless I'm tripping badly, my test paper clearly states that a≤b≤c. Your proof works perfectly fine if you fix up all of the inequality signs.

yep my bad

everyone, listen up! in my proof, all the inequlity signs should be opposite to what they are.

sorry guys! will amend and repost thanks egress

 

[aDimitri]

just checking the soln's in q16bi had a (-1)^n on the numerator of the GP after summed

 

[IR]

BTW WHY IS MULTIPLE CHOICE 6d)?? Am I missing something?

 

[mreditor16]

okay amended proof, thanks again egress