Discussion and Suggested Solutions - Mathematics 2017

[jamonwindeyer]

hey Jamon just wanted to ask, for q16a ii) in the test i  differentiated the length formula in the above part to get dl/dx, then i was stuck and i couldnt find x when dl/dx = 0 so i left it until i finished the rest of the paper. When i came back i had about 15-20min remaining and couldnt for the life of me find x, and so i just guessed random numbers and i actually got the answer. SO without any working out after the differentiation i just wrote x = 3.75 (15/4). then i subbed it into sinalpha and sinbeta and showed that they are equal. How many marks do u think i'd get for that question.

You'll likely lose a mark

Alright understandable Jamon, hope I get lucky hahaha!

Anyways if around 77-80 is raw b6 then what will an 86-88 raw get?

Perhaps mid 90's (<95)?? Really hard to say because the alignment algorithms aren't linear, so I'm unsure when it isn't near a Band cut-off

[Merin Thomas]

Hey am I the only HSC student that dont know how this system works *left out at the corner of the room* anyways, when people say b6 cutoff is eg. 85, does that mean a raw mark of 85? so like... u need to get 85 or above raw to get b6? plus its usually said that above 90% is considered b6. And the bio exam was okayish~ and people expect 93 to be b6 cutoff o.o *jaw drop; pen drop; gasp & clap* so does gettin 91 (above 90) get b6 or should it be above 93 o.o sanks

[jamonwindeyer]

Hey am I the only HSC student that dont know how this system works *left out at the corner of the room* anyways, when people say b6 cutoff is eg. 85, does that mean a raw mark of 85? so like... u need to get 85 or above raw to get b6? plus its usually said that above 90% is considered b6. And the bio exam was okayish~ and people expect 93 to be b6 cutoff o.o *jaw drop; pen drop; gasp & clap* so does gettin 91 (above 90) get b6 or should it be above 93 o.o sanks

Hey! The full guide on the process is here, but you've essentially got it! A Band 6 cutoff of 85 means that anyone with a raw mark of 85 or above will get a B6 equivalent mark as their HSC Exam mark

[Merin Thomas]

thankuuu (: Also, is it true that getting b6 in all units guarantee 90+ atar? (my sub:math, math ext 1, phy, chem, bio, eng stand)

[alihkhan8]

So for that dl/dx question, where it asks show that the value is a minimum, I didnt use calculus to show that it was a minimum. So basically I got the quadratic formula, and there were two solutions, and I just explained how using the other solution will give a maximum (because the square will cancel out the negative.) Yeah it was a really dodgy way of explaining it and I should've used calculus to show it was a min value. I have already accounted this mark as a loss when calculating my raw mark for this exam, but just incase is there any chance that I may have gotten the mark since the question was a 1 marker?

[Krncy]

I don't know if anyone has mentioned this yet, but i think the idea of Question 16)a)ii) is that sina - sinb = dL/dx = 0

[JC13]

Failed...the test was so hard omg.

100% that im getting a band 2-3

[Krncy]

Also, in Question 16) a) ii) you've stated that sin(a) = x/5. Is that not the ratio for tan(a)? should it not be sin(a) = x/sqrt(x^2+5^2)

[PrimalPancake92]

what is the band 6 cut off raw mark?

[PrimalPancake92]

Alright understandable Jamon, hope I get lucky hahaha!

Anyways if around 77-80 is raw b6 then what will an 86-88 raw get?

Then what is the band 6 cutoff for this year?

[jonathanzhou22]

Hey there, thanks for the exam solutions. I have a few thoughts on the exam I'd like to share

I believe for the financial question the final dollar value should be rounded up, not down as otherwise the goal cannot be met. I put down $4020 in my exam, what do you think?

The solution for 16 a) could be made simpler by observing that sin(a) = x / (x^2+25)^2  and sin(b) = (9-x) / (49-(9-x)^2)^2, which means when the derivative equals zero, sin(a) = sin(b).

[alihkhan8]

thankuuu (: Also, is it true that getting b6 in all units guarantee 90+ atar? (my sub:math, math ext 1, phy, chem, bio, eng stand)

A band 6 in even 2 of your subjects and rest mid-high band 5 will get you a 90 atar easily

[blokefromthesky]

hey i am coming 4/6 in my 2 unit class (not alot of ppl do advanced math in my school) and i have an assessment mark of 60. i think i got a 78-80 in the HSC exam. will this land me a band 4 in mathematics in your opinion jamon? i think i already asked on sc but i dont remember the response

[Wowser1212]

What do you think will be the band 5-6 cutoff for this year for raw marks?