Discussion and Suggested Solutions - Mathematics 2017

[navtejkr]

tbh for that area under the curve question, i got k = -2.5
anyone else?

[winstondarmawan]

For the limiting series question, wouldn't there need to be a=/=1,2?

[bimberfairy]

For the limiting series question, wouldn't there need to be a=/=1,2?

I don't believe there should be ? Can I ask how you got that conclusion?

[bimberfairy]

The AP and GP question using simultaneous questions... clever but cheeky nesa

I've never come across a question like that before in the past papers so it shook me for a bit hahaha will have to agree that it was really clever!

[georgiia]

btw what ATARs are you guys going for and what course do you want to do next year?

Atar: >94
and I want to do film 🎬

[jay24495]

Is it fine is I used transversals as my reasoning for that isosceles proving question....BM/MC = BD/DE....then i did the arranging of the equestion they gave and the one I made which was i think same as urs....

[Janey123]

Anyone have any guesses for the raw marks for band allocations this year? For band 5?

[sidzeman]

If we did the questions out of order would that affect our marks in anyway? For example for the cycling question I did part ii in my extra writing book and not before part iii

[dory1866]

Hey Jamon,

re your solution regarding question 16 aii, in which you needed to find x, I found it easier to prove similarity of triangles ace and the other one (equiangular if sina=sinb), then just use ration of sides to find x. came out as 5/7=x/9-x and then solve. less opportunity for calculator mis-entry for the quad formula.

[OliverN]

The question about the three isosceles triangles (15A) the common answer is 36deg but did anyone else also get 108deg as an answer for obtuse-angled triangles? I am fairly sure there are two answers but curious what the general consensus on this is and if NESA is likely to recognise both answers.

[caprese_]

for the kangaroo question, i got 870 because i used the unrounded answer of k . i gave the final answer in 2sf. do you think i will still get the mark?

[BOBBY13579]

what do you guys think the raw mark for state rank would be for this test?

[wilko224]

@caprese_ yeah you should still get the marks

[jamonwindeyer]

Hey, in this do we have to specify that a =/= 2 ? Because if r = 0 then a = 2, but do we have to specify that r =/= 0 ? Thank you

Hey! I discussed this with friends and I think that, since the definition is \(|r|<1\), \(r=0\) is technically an allowable value. The series would be 2+0+0+0...

It is weird but I think allowable!

For the 2 significant figures question shouldn't the answer be 870, considering you use the proper k value? not the approximation, also last question of 11 shouldn't the range be cut off to root 3

The sig figs question is definitely 880, it is standard practice to use the rounded value if it is given to you (they would probably pay you if you used the actual value too though)

The range of that function is infinite, if \(x\) is a large negative value you can get large positive values out

what do you think you would need for a state rank? 99?

Always need 99 or 100 raw, you might scrape in with a 98 this year but usually people are able to get pretty high marks in these exams - I think, at least

What do you think 95 raw would become

High 90's

Jump back to page one and there are expandable spoilers


Also just wondering, I'm probably being a bit paranoid, but how much do they care about the setting out of the working? I'm worried mine might have been too crammed onto the pages even where I spilled into another book. As long as I've underlined all the answers and my writing is legible I should be ok yeah? Also is on the smaller side handwriting still alright cus my writing isn't huge scrawl, like half of the 10mm lines they give so like 5mm 

Underlining your answers will definitely help you, if that underlined answer is correct then they are likely not to pay much attention to the rest (unless it is a proof) - I'm sure you will be fine

[jamonwindeyer]

Would you be able to post up a copy of the exam?

The exam will be posted by NESA very soon, we aren't hosting them ourselves anymore

Jamon how do you reckon this test compares to the one in 2013

From vague memory, this is a harder exam!

Based on the exam solution, I'm looking at around 95-96 raw.

Should align to high 90's

Am I the only one who used similar triangles to solve X in question 16

I'm not sure if it was possible to do it that way! If you post your solution I can let you know what I'd score it?

For questions 16ci, can u use the midpoint theorem of the triangle? and say BD  = DA + AE and its given that BD = DA + AC~ cause i didnt prove that it was simlar triangle and stuff. ~ but i rather stated the mid point formulae theorem ~ WILL THAT BE FINE?

A lot of people seem to have used this result, and I'm not sure - I don't think it is a quotable result but I could be wrong!

I got this answer but accidentally forgot that t> 0 so even though i had the exact last line Jamon has, will i loose a mark for writing that t=0 is a solution?

I reckon you might get off the hook for that - It's such an inconsequential part of the question they might not actually care