Bored of Studies Trial Discussion Thread. (2 Viewers)

nightweaver066

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I didn't even do that part ... too many cases / I didn't see a quick way...
Wouldn't it be 2 cases? When OO is on either end of the word and when OO is elsewhere.

Then 1 - (probability for the above cases)
 

Sy123

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Here are my solutions to the Projectile Motion question:

part i and ii.jpg
part iii and iv.jpg

And for the last question since I ran out of room:



And the physical meaning is that it is faster to project the projectile in one go then to bounce it to its destination?

Not sure about the physical meaning, thats pretty much what it says.
 
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deswa1

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I didn't even do that part ... too many cases / I didn't see a quick way...
You don't need cases- you can do the insertion method. Though I think I forgot about the double H's whoops :(

Here are my solutions to the Projectile Motion question:

View attachment 26457
View attachment 26458

And for the last question since I ran out of room:



And the physical meaning is that it is faster to project the projectile in one go then to bounce it to its destination?

Not sure about the physical meaning, thats pretty much what it says.
Fuark- did you get all of the last question? What mark do you think you got? What a best- WOW
 

medicore

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Here are my solutions to the Projectile Motion question:

View attachment 26457
View attachment 26458

And for the last question since I ran out of room:



And the physical meaning is that it is faster to project the projectile in one go then to bounce it to its destination?

Not sure about the physical meaning, thats pretty much what it says.
Wow year 11 and you're this talented, well done! Looking at a 99 ATAR, yeah? ahah.
 

bleakarcher

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Deswa, did you just not have enough time for the projectile motion questions?
 

deswa1

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Deswa, did you just not have enough time for the projectile motion questions?
Yeah pretty much. I'm not sure if I would have been able to do it though even if I had time- I'll try it at home. How'd you go?
 

Sy123

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You don't need cases- you can do the insertion method. Though I think I forgot about the double H's whoops :(



Fuark- did you get all of the last question? What mark do you think you got? What a best- WOW
I had a case of stomach acid since the early morning, taking the antacid tablets didnt work, and my stomach just failed me all throughout the exam the pain didnt allow me to concentrate or do anything :(
So I just stopped doing the exam after Q11 and Pmed carrot my situation. I went to sleep for like 3 hours and came back a bit better and did the last question for fun lol. If I did the exam under time though I dont think I would have enough time.

And also lol since I did Q11 but nothing else because of my stupid stomach, I didnt know how to do the last perms one. I got: 10 080, probably wrong heh.
(and the binomial multiple choice Q2, is multiples of 3 right?)
 

bleakarcher

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Yeah pretty much. I'm not sure if I would have been able to do it though even if I had time- I'll try it at home. How'd you go?
Well, the projectile motion question I thought was one of the easier questions in the paper but I guess this would change from person to person. Overall, I did pretty shit though in my opinion. Didn't do Q11) b) iii), Q12) c) iii), Q11) d) (knew what to do but read the question incorrectly, got confused and moved on) and left out all the binomial questions lol.
 

bleakarcher

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I had a case of stomach acid since the early morning, taking the antacid tablets didnt work, and my stomach just failed me all throughout the exam the pain didnt allow me to concentrate or do anything :(
So I just stopped doing the exam after Q11 and Pmed carrot my situation. I went to sleep for like 3 hours and came back a bit better and did the last question for fun lol. If I did the exam under time though I dont think I would have enough time.

And also lol since I did Q11 but nothing else because of my stupid stomach, I didnt know how to do the last perms one. I got: 10 080, probably wrong heh.
(and the binomial multiple choice Q2, is multiples of 3 right?)
Yeah I'm sick too. I feel like fucking shit. This cold has fucked my day for the past few days.

Also, yeah I got n must be a multiple of 3 as well.
 

deswa1

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(and the binomial multiple choice Q2, is multiples of 3 right?)
Yeah I'm pretty sure- that's what I got. Hopefully I got 10/10 for MC (not sure though)- only question I've got a chance of full marks lol

Well, the projectile motion question I thought was one of the easier questions in the paper but I guess this would change from person to person. Overall, I did pretty shit though in my opinion. Didn't do Q11) b) iii), Q12) c) iii), Q11) d) (knew what to do but read the question incorrectly, got confused and moved on) and left out all the binomial questions lol.
Oh really? Ok will try at home. It was an interesting question though- never seen anything like it before.

And inb4 we all get raped on Wednesday
 

bleakarcher

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Yeah I'm pretty sure- that's what I got. Hopefully I got 10/10 for MC (not sure though)- only question I've got a chance of full marks lol



Oh really? Ok will try at home. It was an interesting question though- never seen anything like it before.

And inb4 we all get raped on Wednesday
lol'd

but yeah don't know what to expect from the 4U paper. Hopefully I get better so that I can attempt it to my full potential.
 

barbernator

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My multiple choice answers:

1. B
2. C
3. D
4. A
5. C
6. B
7. D
8. D
9. B
10. D

anyone the same or different?
 

Sy123

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The first one is D, the period is


And the acclereation is:

So n=b, so the period is 2pi/b rather than just b :/

But other than that I got the same as you (except for 8, but I rechecked my answer and I found a mistake, and found that yours was right)
 

barbernator

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The first one is D, the period is


And the acclereation is:

So n=b, so the period is 2pi/b rather than just b :/

But other than that I got the same as you (except for 8, but I rechecked my answer and I found a mistake, and found that yours was right)
oh yeh whoops :3
 

Sy123

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Did anyone get the last perms question? part biii of Q11
 

barbernator

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Did anyone get the last perms question? part biii of Q11
I have a feeling carrot may have underestimated its difficulty. If there was no double H's it would have been fine... but maybe there is an easy way
 

Carrotsticks

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Seeing some really impressive stuff from some of you guys =)

I have a feeling carrot may have underestimated its difficulty. If there was no double H's it would have been fine... but maybe there is an easy way
There is an easy way that does NOT require the use of cases.
 

Carrotsticks

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ahhh yes! this is very similar to what you were explaining in your MX2 seminar. just do whatever it says (in this case x n/2) and play with it from there. Will post working.

<a href="http://www.codecogs.com/eqnedit.php?latex=from~ii)\\\\ \frac{n}{2}\sum_{r=0}^{n}\binom{n}{r}^{2}=\frac{n}{2}\binom{2n}{n}\\\\ \frac{n}{2}(\binom{n}{0}^{2}@plus;\binom{n}{1}^{2}@plus;...@plus;\binom{n}{n}^{2})=\frac{n}{2}\binom{2n}{n}\\\\ n(\binom{n}{0}^{2}@plus;\binom{n}{1}^{2}@plus;...@plus;\binom{n}{n/2}^{2})=\frac{n}{2}\binom{2n}{n}(by~symmetry)\\\\ 0\binom{n}{0}^{2}@plus;n\binom{n}{n}^{2}@plus;1\binom{n}{1}^{2}@plus;(n-1)\binom{n}{n-1}^{2}@plus;...=\frac{n}{2}\binom{2n}{n}(again~by~symmetry)\\\\\therefore \sum_{r=0}^{n}r\binom{n}{r}^{2}=\frac{n}{2}\binom{2n}{n}~as~required." target="_blank"><img src="http://latex.codecogs.com/gif.latex?from~ii)\\\\ \frac{n}{2}\sum_{r=0}^{n}\binom{n}{r}^{2}=\frac{n}{2}\binom{2n}{n}\\\\ \frac{n}{2}(\binom{n}{0}^{2}+\binom{n}{1}^{2}+...+\binom{n}{n}^{2})=\frac{n}{2}\binom{2n}{n}\\\\ n(\binom{n}{0}^{2}+\binom{n}{1}^{2}+...+\binom{n}{n/2}^{2})=\frac{n}{2}\binom{2n}{n}(by~symmetry)\\\\ 0\binom{n}{0}^{2}+n\binom{n}{n}^{2}+1\binom{n}{1}^{2}+(n-1)\binom{n}{n-1}^{2}+...=\frac{n}{2}\binom{2n}{n}(again~by~symmetry)\\\\\therefore \sum_{r=0}^{n}r\binom{n}{r}^{2}=\frac{n}{2}\binom{2n}{n}~as~required." title="from~ii)\\\\ \frac{n}{2}\sum_{r=0}^{n}\binom{n}{r}^{2}=\frac{n}{2}\binom{2n}{n}\\\\ \frac{n}{2}(\binom{n}{0}^{2}+\binom{n}{1}^{2}+...+\binom{n}{n}^{2})=\frac{n}{2}\binom{2n}{n}\\\\ n(\binom{n}{0}^{2}+\binom{n}{1}^{2}+...+\binom{n}{n/2}^{2})=\frac{n}{2}\binom{2n}{n}(by~symmetry)\\\\ 0\binom{n}{0}^{2}+n\binom{n}{n}^{2}+1\binom{n}{1}^{2}+(n-1)\binom{n}{n-1}^{2}+...=\frac{n}{2}\binom{2n}{n}(again~by~symmetry)\\\\\therefore \sum_{r=0}^{n}r\binom{n}{r}^{2}=\frac{n}{2}\binom{2n}{n}~as~required." /></a>
Just read this a bit more carefully. What if n is odd? non-integer factorials are not defined in the HSC Syllabus.

Here are my solutions to the Projectile Motion question:

View attachment 26457
View attachment 26458

And for the last question since I ran out of room:



And the physical meaning is that it is faster to project the projectile in one go then to bounce it to its destination?

Not sure about the physical meaning, thats pretty much what it says.
Very impressive, you are correct!

lol'd

but yeah don't know what to expect from the 4U paper. Hopefully I get better so that I can attempt it to my full potential.
3 people missed out due to illnesses. I hope the best for all of them.
 

barbernator

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Just read this a bit more carefully. What if n is odd? non-integer factorials are not defined in the HSC Syllabus.
I was thinking about that before actually. Maybe just tell the odd integers to piss off?
 

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