Bored of Studies Trial Discussion Thread. (2 Viewers)

[deswa1]

I took one look at you and deswa during the first 15 minutes and I could tell straight away that it was living up to the hype (deswa's body language was all over the place - obligatory no crepe).

Haha really? Lol I've always wanted to see myself in an exam- even ones I'm confident in I always spin my pen or ruffle my hair or whatever but here it would have been particularly pronounced I'm guessing- I probs looked like a retard haha. But I'm not the easily not the best at maths on BOS- would be interesting to see what the top mark is and what their reactions were like

 

[enoilgam]

Haha really? Lol I've always wanted to see myself in an exam- even ones I'm confident in I always spin my pen or ruffle my hair or whatever but here it would have been particularly pronounced I'm guessing- I probs looked like a retard haha. But I'm not the easily not the best at maths on BOS- would be interesting to see what the top mark is and what their reactions were like

You were doing this a lot - I could tell you werent very confident with it.

 

[zb123]

How do you do question 2, and can someone explain the binomial solution, don't know how symmetry comes into play?.

 

[king chopper]

Carrot, can you please post solutions??

 

[deswa1]

Reworking through the paper now (doing all the ones I missed on the day). And Carrot you're going to kill me when you see some inefficient solutions - some of the questions I'm redoing I'm realising that there is actually an easy way to do it lol

Edit: Does anyone know how to 13 d) ii) 2? - that's the one with the acceleration. Also just found more silly errors lol- hopefully above 45/70 lol (64% haha). inb4 I actually fail my first maths test on Wed

 

[Sy123]

Reworking through the paper now (doing all the ones I missed on the day). And Carrot you're going to kill me when you see some inefficient solutions - some of the questions I'm redoing I'm realising that there is actually an easy way to do it lol

Edit: Does anyone know how to 13 d) ii) 2? - that's the one with the acceleration. Also just found more silly errors lol- hopefully above 45/70 lol (64% haha). inb4 I actually fail my first maths test on Wed

For Q11 a, is there an efficient solution, or is it just t formula and then polynomial division? Thats what I did but I feel like there should be a faster way

 

[deswa1]

For Q11 a, is there an efficient solution, or is it just t formula and then polynomial division? Thats what I did but I feel like there should be a faster way

Why do you need polynomial division? When you use t formulae- it should factorise very nicely unless I made a mistake?

 

[deswa1]

Ok went through the rest of the paper which was good. I still don't know how to do the acceleration question in the very last part of Q13 but except for that, I think I now know how to do everything (and I also realised I made so many retarded mistakes on the day lol). The projectile was heaps nice- I liked that

 

[Carrotsticks]

How do you do question 2, and can someone explain the binomial solution, don't know how symmetry comes into play?.

What part of Q2? And for the Binomial Q, I originally had a decently useful trick in mind to solve it.

However, Trebla raised that there was another way to do it too (symmetry), as well as the one I had. I gave you guys the symmetry clue beforehand because I figured it might be more accessible as an intuitive thing under exam pressure.

Will post Binomial method once I get home. Unless Trebla does the honours for me.

Carrot, can you please post solutions??

Not yet.

Reworking through the paper now (doing all the ones I missed on the day). And Carrot you're going to kill me when you see some inefficient solutions - some of the questions I'm redoing I'm realising that there is actually an easy way to do it lol

It's part of the process. The idea was for YOU to see how you perform when you are put under stress. This will inevitably involve brute force methods and 'inefficient solutions'. It is something I was prepared for, and expected.

You would much rather find out now, as opposed to in the HSC exam when it's too late.

 

[Carrotsticks]

Reworking through the paper now (doing all the ones I missed on the day). And Carrot you're going to kill me when you see some inefficient solutions - some of the questions I'm redoing I'm realising that there is actually an easy way to do it lol

Edit: Does anyone know how to 13 d) ii) 2? - that's the one with the acceleration. Also just found more silly errors lol- hopefully above 45/70 lol (64% haha). inb4 I actually fail my first maths test on Wed

On phone ATM so I'll do what I can.

You want to find the second derivative, which is A double dot. Or in other words

dA(dot)/dt = dA(dot)/da x da/dt

For Q11 a, is there an efficient solution, or is it just t formula and then polynomial division? Thats what I did but I feel like there should be a faster way

No polynomial long division is necessary. It factorises neatly.

 

[zb123]

Q2 multiple choice, how do u solve the question? Like what values of n..

 

[Sy123]

Q2 multiple choice, how do u solve the question? Like what values of n..

Lets find the general rth term of the expansion which will give us a constant term:



Lets disregard co-efficients for now and find r such that we get x^0 in the end:



We have found a result that tells us this, for any r-integer, 3 times this integer will give us an expansion with a constant. Hence for every multiple of 3 in n, will give us a constant term.

 

[Trebla]

As per the hint:



Directly expand this sum and you should realise that this gives the same expansion as

 

[Timske]

omfg spent 30mins on Q12, subbed in as .2at+at^2

 

[Trebla]

Edit: Does anyone know how to 13 d) ii) 2? - that's the one with the acceleration. Also just found more silly errors lol- hopefully above 45/70 lol (64% haha). inb4 I actually fail my first maths test on Wed

Use of the chain rule as Carrot mentioned before. Notice that the acceleration expressed in this way is analogous to the v(dv/dx) form.

 

[barbernator]

just thought if an extra part that could be added to the final question.

if <a href="http://www.codecogs.com/eqnedit.php?latex=V_{0}=kV_R" target="_blank"><img src="http://latex.codecogs.com/gif.latex?V_{0}=kV_R" title="V_{0}=kV_R" /></a> find k in terms of <a href="http://www.codecogs.com/eqnedit.php?latex=\theta" target="_blank"><img src="http://latex.codecogs.com/gif.latex?\theta" title="\theta" /></a> such that the range of each projectile is still equal.

 

[Carrotsticks]

just thought if an extra part that could be added to the final question.

if find k in terms of such that the range of each projectile is still equal.

Interesting. Will look at it later, but have to sort out other things at the moment.

And for the trick I was talking about before....

Replace k with n-k, and see what happens (kinda like substitution method for integration).

It is in a sense the same thing as using the symmetric property of the binomial terms.

 

[chriss95]

Had a go at the ext 1 paper here at home. Definitely much more difficult than most other trials. I've managed to pretty much get everything up q14; which is where I'm at now. Circle geometry is just construct PT and QT, and they are right angles (angle in a semi-circle is a right angle) -> BC subtends equal angles at two distinct points?

 

[Timske]

Had a go at the ext 1 paper here at home. Definitely much more difficult than most other trials. I've managed to pretty much get everything up q14; which is where I'm at now. Circle geometry is just construct PT and QT, and they are right angles (angle in a semi-circle is a right angle) -> BC subtends equal angles at two distinct points?

angle Apt = 90 ? how does that help

 

[chriss95]

apt = 90 -> bpt = 90
aqt = 90 -> cqt = 90

therefore BC subtends equal angles at two distinct points P and Q