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March 28, 2024, 09:51:01 pm

Author Topic: 3U Maths Question Thread  (Read 1230210 times)  Share 

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massive

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Re: 3U Maths Question Thread
« Reply #705 on: October 01, 2016, 04:33:05 pm »
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(Image removed from quote.)Read the question again. b and a are actually y-coordinates, not x-coordinates

(Or technically I should say they are x-coordinates and not t-coordinates)

They can definitely both be stationary points because SHM is described by a sine curve, which has infintely many stationary points

OHH but when it says "whose distances from the same side of the origin..." isn't the origin referring to the centre of motion?

RuiAce

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3U Maths Question Thread
« Reply #706 on: October 01, 2016, 05:26:06 pm »
+1
OHH but when it says "whose distances from the same side of the origin..." isn't the origin referring to the centre of motion?
Recall: The origin is x=0 for our purposes of analysing motion

It just means that additionally 0<a<b or a<b<0
« Last Edit: October 01, 2016, 05:29:34 pm by RuiAce »

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Re: 3U Maths Question Thread
« Reply #707 on: October 03, 2016, 10:15:28 am »
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Hi, could someone please explain how to work through this question (both parts) ? I've looked through the solutions and it still doesn't make much sense

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Re: 3U Maths Question Thread
« Reply #708 on: October 03, 2016, 10:35:24 am »
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Hi, could someone please explain how to work through this question (both parts) ? I've looked through the solutions and it still doesn't make much sense





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Re: 3U Maths Question Thread
« Reply #709 on: October 04, 2016, 10:29:24 pm »
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hiya folk! This is from the 2012 HSC exam (Question 11). I understand how to do part i of the question, but part ii is like...waht?
I'm mainly confused about what a 'Non-zero constant term' is.


Thanks for the help!

RuiAce

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Re: 3U Maths Question Thread
« Reply #710 on: October 04, 2016, 10:43:16 pm »
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hiya folk! This is from the 2012 HSC exam (Question 11). I understand how to do part i of the question, but part ii is like...waht?
I'm mainly confused about what a 'Non-zero constant term' is.


Thanks for the help!





As an exercise, you may wish to expand (2x3-1/x)n on WolframAlpha. Use n=1,2,3,5,6,7,9,10,11 and you will find there is no constant term (or in other words, the constant term is 0). When n=4,8,12,... however, you'll find you get a constant

Edit: Actually Jake answered this one already. Refer to post 601.
« Last Edit: October 05, 2016, 08:47:00 am by RuiAce »

fizzy.123

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Re: 3U Maths Question Thread
« Reply #711 on: October 05, 2016, 01:32:45 am »
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how do we answer iii? (2014 MX1)

lha

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Re: 3U Maths Question Thread
« Reply #712 on: October 05, 2016, 08:51:09 am »
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Could someone please help me with question 14b)iii) from the 2013 hsc paper?

jakesilove

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Re: 3U Maths Question Thread
« Reply #713 on: October 05, 2016, 09:29:40 am »
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how do we answer iii? (2014 MX1)

From part ii) we find that the slope of the line is t. We also know from part i) that



The important thing to note here is that the gradient t is equal to RISE OVER RUN, and thus



From there, just sub all t values in for y/x (for either x or y equations above, although I think x is easier), solve the equation, and you'll get a circle out. A tough question for sure!

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Re: 3U Maths Question Thread
« Reply #714 on: October 05, 2016, 09:32:57 am »
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Could someone please help me with question 14b)iii) from the 2013 hsc paper?

If you could post the actual question in the future that'd be awesome.

I think the Board of Studies does a good job with this answer, so I've just posted it below. Let me know if you need any clarification on any particular line or working; I feel like it is probably clear, and to be honest I'm not good enough at LaTeX to type out a proper answer.



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Re: 3U Maths Question Thread
« Reply #715 on: October 05, 2016, 10:02:53 am »
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If you could post the actual question in the future that'd be awesome.

I think the Board of Studies does a good job with this answer, so I've just posted it below. Let me know if you need any clarification on any particular line or working; I feel like it is probably clear, and to be honest I'm not good enough at LaTeX to type out a proper answer.

(Image removed from quote.)

Jake

No this is fine, thank you!

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Re: 3U Maths Question Thread
« Reply #716 on: October 05, 2016, 11:11:42 am »
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No this is fine, thank you!

No problem! I always hated these kinds of questions (still do), so if you find that you struggle with them, don't worry! In my opinion, they are the most difficult maths you do in the 3U course (ie, really hard binom questions) just because of the terminology, logic and guesswork that is required.
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Re: 3U Maths Question Thread
« Reply #717 on: October 05, 2016, 02:39:50 pm »
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No problem! I always hated these kinds of questions (still do), so if you find that you struggle with them, don't worry! In my opinion, they are the most difficult maths you do in the 3U course (ie, really hard binom questions) just because of the terminology, logic and guesswork that is required.
2013 binomial theorem question was insane though to be fair.

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Re: 3U Maths Question Thread
« Reply #718 on: October 05, 2016, 03:43:43 pm »
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2013 binomial theorem question was insane though to be fair.

Doing it for the MX1 Revision lecture brought back nightmares ;)

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Re: 3U Maths Question Thread
« Reply #719 on: October 05, 2016, 03:45:22 pm »
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Doing it for the MX1 Revision lecture brought back nightmares ;)
You just purposely chose to bring back many baaaad memories