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March 29, 2024, 09:22:16 am

Author Topic: VCE Methods Question Thread!  (Read 4802813 times)  Share 

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aspiringantelope

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Re: VCE Methods Question Thread!
« Reply #18135 on: September 21, 2019, 03:22:53 pm »
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HARD QUESTION !!!
Two signposts are 100 km apart on the tollway.
There are six complete sections of road between these two signposts.
The lengths of the successive sections of road increase by 5%.
Determine the length of the first section of road.

THANKS :)
Irrelevant but according to your signature, haven't you completed VCE?

TrueTears

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Re: VCE Methods Question Thread!
« Reply #18136 on: September 23, 2019, 06:12:54 am »
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Not sure how to approach the following question
I understand how to do a and b but is there an easier way to do c? It seems way to tedious to do by hand.

A company employs a sales team of 20 people, consisting of 12 men and 8 women
a) what is p, the proportion of men in the sales team
b) Five salespeople are to be selected at random to attend an important conference. What are the possible values of the same proportion ^p of men in the sample.
c) Construct a probability distribution table which summarises the sampling distribution of the sample proportion of men when sample of size 5 are selected from the sales team.

(Chapter 17B q2 from Cambridge Mathematical Methods Units 3&4 book )
Here, you can calculate the exact sampling distribution by hand (yes it's tedious). If the sample size was much larger, then the sampling distribution can be approximated by a normal distribution.
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Re: VCE Methods Question Thread!
« Reply #18137 on: September 23, 2019, 08:06:11 pm »
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Just out of sheer curiosity, what would happen if your CAS dies early on during the exam?

I can't say with 100% certainty, but I'm fairly sure that VCAA expects you to be responsible for bringing a functional and charged CAS to the exam so they won't have any spares available on the day, especially as there are multiple different approved calculators so they can't possibly accommodate for everyone.

Also I couldn't find anything on this page (approved tech for VCAA maths exams) so I would assume there's no spare calculators available.

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Sine

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Re: VCE Methods Question Thread!
« Reply #18138 on: September 23, 2019, 08:27:16 pm »
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Just out of sheer curiosity, what would happen if your CAS dies early on during the exam?
Probably nothing - would need to do everything by hand.

However, something you could do if you have two CAS's is to give one to the assessors before the start of the exam and ask for it if your CAS dies. Obviously would be very assessor dependent on how nice they are. Keep in mind you can only take in one CAS calc.

Also you could take a scientific calculator alongside your CAS as back up for small calculations - obviously wouldn't be able to do any calculus.

Just another student

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Re: VCE Methods Question Thread!
« Reply #18139 on: September 27, 2019, 10:50:19 am »
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VCAA 2007 Q21:

{x: cos^2(x) + 2cos (x) = 0} =

Can someone please explain why the answer is : {x : cos (x) = 0}



Tau

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Re: VCE Methods Question Thread!
« Reply #18140 on: September 27, 2019, 11:15:05 am »
+1
VCAA 2007 Q21:

{x: cos^2(x) + 2cos (x) = 0} =
Can someone please explain why the answer is : {x : cos (x) = 0}

\( (\cos(x))^2 + 2\cos (x) =0 \implies \cos(x)=\frac{-2\pm \sqrt{4-4(1)(0)}}{2(1)} = \frac{-2\pm2}{2}=-2,0.\)

But \(\cos(x)\ne -2 \implies \cos(x)=0\). Where the quadratic formula was used above to find a solution for \(\cos(x)\).
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Re: VCE Methods Question Thread!
« Reply #18141 on: September 27, 2019, 01:56:45 pm »
+1
\( (\cos(x))^2 + 2\cos (x) =0 \implies \cos(x)=\frac{-2\pm \sqrt{4-4(1)(0)}}{2(1)} = \frac{-2\pm2}{2}=-2,0.\)

But \(\cos(x)\ne -2 \implies \cos(x)=0\). Where the quadratic formula was used above to find a solution for \(\cos(x)\).
Why are you using the quadratic formula? when you can literally just do


Tau

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Re: VCE Methods Question Thread!
« Reply #18142 on: September 27, 2019, 01:59:24 pm »
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Why are you using the quadratic formula? when you can literally just do



That’s fair, works faster and less error prone to factorise. Regardless, same answer.
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Just another student

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Re: VCE Methods Question Thread!
« Reply #18143 on: September 27, 2019, 02:02:25 pm »
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Why are you using the quadratic formula? when you can literally just do




Thanks for the reply, how did simply the equation? like go from first to second step and get rid of the squared?
Also thanks Tau for your approach too!

aspiringantelope

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Re: VCE Methods Question Thread!
« Reply #18144 on: September 27, 2019, 02:23:19 pm »
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Thanks for the reply, how did simply the equation? like go from first to second step and get rid of the squared?
Also thanks Tau for your approach too!
Take cos(x) out

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Re: VCE Methods Question Thread!
« Reply #18145 on: September 27, 2019, 02:37:48 pm »
+7
It's basic laws of algebra that you learn in year 7 or so?

I don't get what part of that your confused at and why? It's really trivial
Hey, moderator here. This is not an appropriate comment.

You may understand it, but by no means is it okay to label someone's confusion over a subject you find simple 'trivial'.

Please respect others and their individual challenges on this forum.
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DrDusk

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Re: VCE Methods Question Thread!
« Reply #18146 on: September 27, 2019, 02:43:18 pm »
+2
Hey, moderator here. This is not an appropriate comment.

You may understand it, but by no means is it okay to label someone's confusion over a subject you find simple 'trivial'.

Please respect others and their individual challenges on this forum.
My bad. Upon further inspection I do realize it is being harsh.

Sorry mate @Just another student, I mean no harm =)

Just another student

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Re: VCE Methods Question Thread!
« Reply #18147 on: September 27, 2019, 03:33:09 pm »
+1
My bad. Upon further inspection I do realize it is being harsh.

Sorry mate @Just another student, I mean no harm =)

I literally can't believe I didn't see that, I guess I had a bit of a mind blank. Yes I agree it's something I should have learned a long time ago and am definitely familiar with that hahah. No worries thanks for the help.

Just another student

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Re: VCE Methods Question Thread!
« Reply #18148 on: September 27, 2019, 08:08:07 pm »
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https://www.vcaa.vic.edu.au/assessment/vce-assessment/past-examinations/Pages/Mathematical-Methods.aspx

Can someone please explain VCAA 2008 MC Q19? (the question with graph of antiderivative)

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Re: VCE Methods Question Thread!
« Reply #18149 on: September 27, 2019, 08:14:14 pm »
+2
https://www.vcaa.vic.edu.au/assessment/vce-assessment/past-examinations/Pages/Mathematical-Methods.aspx

Can someone please explain VCAA 2008 MC Q19? (the question with graph of antiderivative)

Hey there!

Essentially, when you take one of the multiple choice options, the derivative is the given graph. Noting this, we see that the derivative is always positive and greater than zero --> no turning points! though it comes close as the graph approaches large values of x. Hence, the answer must be B, since A and C have turning points, E is decreasing for all x, and D isn't even a function!

Hope this helps :)
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