HSC 2012 MX2 Marathon (archive) (4 Viewers)

[Nooblet94]

Re: 2012 HSC MX2 Marathon

I got

Shit. That's wrong, nightweaver's right. (forgot to finish off one of the inequalities lol)

 

[nightweaver066]

Re: 2012 HSC MX2 Marathon

lol don't sweat it, we all make mistakes.

 

[Carrotsticks]

Re: 2012 HSC MX2 Marathon

Correct, but it's debatable whether there should be equality for the -1/3 side of the inequality.

Reason being d=-1/3 gives the degenerate 'triangle', which is just a straight line.

And the 'axiom of triangle' you mentioned is more famously known as the "Triangle Inequality" haha.

 

[math man]

Re: 2012 HSC MX2 Marathon

but lets all agree, that for a q8 from a previous trial, this question is rather pathetic in that sense, more suited for q4,5,6

 

[nightweaver066]

Re: 2012 HSC MX2 Marathon

 

[Nooblet94]

Re: 2012 HSC MX2 Marathon

but lets all agree, that for a q8 from a previous trial, this question is rather pathetic in that sense, more suited for q4,5,6

Yep, entirely. The only remotely challenging part is knowing to apply the triangle inequality and it's extension 2 maths, so everyone should be able to make basic logical connections like that.

 

[nightweaver066]

Re: 2012 HSC MX2 Marathon

Yep, entirely. The only remotely challenging part is knowing to apply the triangle inequality and it's extension 2 maths, so everyone should be able to make basic logical connections like that.

A question similar to this was in my 2U preliminary half yearly test last year. Only a handful of students got it lol.

 

[crazy_paki123]

Re: 2012 HSC MX2 Marathon

hey, hey, hey im new. can sum1 tell me how to start new threads nd rite my courses nd atar aim. thanx. much appreciated

 

[Nooblet94]

Re: 2012 HSC MX2 Marathon

Yep, entirely. The only remotely challenging part is knowing to apply the triangle inequality and it's extension 2 maths, so everyone should be able to make basic logical connections like that.

EDIT:
For nightweavers question I got , but I honestly wouldn't be surprised if that's wrong considering how I've been going this evening.

Actual Edit:
FUCK. Meant to edit my post, not reply to it. I really need to go to bed.

 

[bleakarcher]

Re: 2012 HSC MX2 Marathon

^ I got 0.

 

[nightweaver066]

Re: 2012 HSC MX2 Marathon

EDIT:
For nightweavers question I got , but I honestly wouldn't be surprised if that's wrong considering how I've been going this evening.

Actual Edit:
FUCK. Meant to edit my post, not reply to it. I really need to go to bed.

Haha.. not correct. Try again tomorrow when you're feeling fresh.

 

[bleakarcher]

Re: 2012 HSC MX2 Marathon

Dont worry Nooblet, get some rest. I have bad days as well.

 

[Carrotsticks]

Re: 2012 HSC MX2 Marathon

^ I got 0.

I got 0.

 

[nightweaver066]

Re: 2012 HSC MX2 Marathon

Correct. I hope no-one tried modulus argument lol.

 

[Aesytic]

Re: 2012 HSC MX2 Marathon

(i) angle NPC = angle CBP (alternate segment theorem)
angle PNC = 90 (given)
.'. angle NCP = 180 - 90 - angle NPC (angle sum of a triangle is 180)
= 90 - angle NPC
angle ACB = 90 (angle subtended at the circumference from a diameter is a right angle)
since angle ACB = angle NCP + angle PCB,
.'. 90 = 90 - angle NPC + angle PCB
.'. angle NPC = angle PCB
.'. angle CBP = angle PCB
.'. PC = PB (sides opposite equal angles in a triangle are equal)

(ii) angle PNC = 90 (given)
.'. angle NPC + angle NCP = 90 (angle sum of a triangle is 180)
since angle NPC = angle APC + angle NPA,
.'. angle APC + angle NPA + angle ACP = 90
angle NPA = angle ACP (alternate segment theorem)
.'. angle APC + 2*angle ACP = 90

(iii) let angle PAB = x
angle APB = 90 (angle subtended at circumference by a diameter is a right angle)
.'. angle PBA = 90 - x (angle sum of a triangle is 180)
angle PBA = angle PCA (angles subtended by the same arc are equal)
.'. angle PCA = 90 - x
angle PNC = 90 (given)
.'. angle NPC = 90 - angle PCA (angle sum of a triangle is 180)
.'. angle NPC = 90 - (90 - x)
= x
.'. angle PAB = angle NPC

 

[nightweaver066]

Re: 2012 HSC MX2 Marathon

Qn:

 

[Nooblet94]

Re: 2012 HSC MX2 Marathon

Haha.. not correct. Try again tomorrow when you're feeling fresh.

Oh god. That's so embarrasing. The legal notes I was writing last night are complete shit as well. Guess I really need to sleep more

 

[SpiralFlex]

Re: 2012 HSC MX2 Marathon

Always sleep.

I got pwned in the 2U test lolololol as a result.

 

[deswa1]

Re: 2012 HSC MX2 Marathon

Always sleep.

I got pwned in the 2U test lolololol as a result.

Not sure if serious. Regardless it doesn't matter for you. I got 42/55 in my 2U test because I did it without a calculator to see how I'd go (trig became my new enemy...)

 

[SpiralFlex]

Re: 2012 HSC MX2 Marathon

Not sure if serious. Regardless it doesn't matter for you. I got 42/55 in my 2U test because I did it without a calculator to see how I'd go (trig became my new enemy...)

I am serious. >_>

I came near bottom out of 117 hahaha. I thought I got everything correct...I skipped questions (Oops).