# BoS Maths Trials 2017 (1 Viewer)

#### SaltSolutionPromo

##### New Member
Before the respective HSC exam

Though feel free to request hints/short solutions to any particular question you want an answer for now
For the Q11 (c)(i) vectors question, after using the triangular inequality, how do you come to the inequality you're required to prove? I can't seem to work out how to algebra this.

#### Trebla

For the Q11 (c)(i) vectors question, after using the triangular inequality, how do you come to the inequality you're required to prove? I can't seem to work out how to algebra this.
Use the triangle inequality on the LHS then expand and simplify

#### InteGrand

##### Well-Known Member
For the Q11 (c)(i) vectors question, after using the triangular inequality, how do you come to the inequality you're required to prove? I can't seem to work out how to algebra this.
Basically the sum of the terms inside the absolute values on the LHS is equal to the expression in the absolute values on the RHS (that is, (a-b)(c-d) + (a-d)(b-c) = (a-c)(b-d)). So the result follows from the triangle inequality (|z| + |w| ≥ |z + w|).

#### Raeservoir

##### New Member
Just to check, is it too much to ask to see our papers? Only if it's not a hassle, wouldn't mind seeing the places where I screwed up when I shouldn't have

(I haven't looked at the paper since, decided past HSC papers were a bit more down to earth wew)

#### aycaramba

##### Member
keen for the solutions & results. hope I get at least 5%

#### strawberrye

It might be difficult since all the papers were separated question by question for marking in different piles, and there is a lot of pages that needs to be scanned for one person, and given that the organisers are doing it on a voluntary basis and they have full time work (the people who wrote the exams), it is highly unlikely they will have the time to do that... except in exceptional circumstances or by exercise of their personal discretion.

#### Raeservoir

##### New Member
It might be difficult since all the papers were separated question by question for marking in different piles, and there is a lot of pages that needs to be scanned for one person, and given that the organisers are doing it on a voluntary basis and they have full time work (the people who wrote the exams), it is highly unlikely they will have the time to do that... except in exceptional circumstances or by exercise of their personal discretion.
Ah right, that's okay. Thanks though, I'll keep my eye out for the answers + the final marks then ^^

##### -insert title here-
Just to check, is it too much to ask to see our papers? Only if it's not a hassle, wouldn't mind seeing the places where I screwed up when I shouldn't have

(I haven't looked at the paper since, decided past HSC papers were a bit more down to earth wew)
I'm looking into this possibility, but the decision ultimately lies with Carrotsticks and Trebla.

#### Carrotsticks

##### Retired
It might be difficult since all the papers were separated question by question for marking in different piles, and there is a lot of pages that needs to be scanned for one person, and given that the organisers are doing it on a voluntary basis and they have full time work (the people who wrote the exams), it is highly unlikely they will have the time to do that... except in exceptional circumstances or by exercise of their personal discretion.
This. Thank you for explaining, Strawberrye.

#### Trebla

Hey, when will the marks be shown to the forum? If they have already is it possible for a link? Thank you very much!
Soon. Give it a couple more hours

#### apinix

##### New Member
Soon. Give it a couple more hours
Does that mean solutions will be out as well?

##### -insert title here-
when one person is out of commission for a few hours and everyone stays up late getting solutions together :')

#sleep4days

Boom

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#### calamebe

##### Active Member
Hey, could someone hint me how to do the first part of the pyramid question in the Extension 1 Paper? Its the only one i still cant get
Extend OP to hit the triangle QRS at M, then calculate MP in two different ways.

#### mathpie

##### New Member
what schools came to the top?

#### Green Yoda

##### Hi Φ
Moderator
Congrats Calamebe with the new record

#### Carrotsticks

##### Retired
when one person is out of commission for a few hours and everyone stays up late getting solutions together :')

#sleep4days
Who was out of commission? I'll ban them.

#### pikachu975

##### I love trials
Moderator
Did better than I thought

Congrats on the 74 calamebe new record

8/15 in that q16 is crazy

#### seanieg89

##### Well-Known Member
What is the reasoning behind the second line of the estimate for |Q(k*alpha)| in the solution to Q16h) ?

As written, that does not seem complete to me.

#### Raeservoir

##### New Member
>dying at someone getting 8/15 congrats Calamebe
Did a little worse than I thought, 50/58 for the marks I attempted. *shrugs* thanks for your time though everyone!