/0's Methods thread

[methodsboy]

where is this question from?

[/0]

So far just from Essential Math Methods CAS Revision Chapters

[/0]

Just a few concerns, (a lot of them finicky [sorry!] but who knows what kind of examiner you'll get)

1. Do they mind if we write way over the lines? Can you request extra paper for questions (even if they are only 1-2 line questions)?
e.g. In VCAA 2007 Exam 1 Question 12
I wrote for the whole page right down to the bottom but there were only half a page of lines.

2. Is the notation allowed? I remember seeing this question somewhere else on this forum but I forgot the answer :p

3. Is it correct/incorrect to define and then
*working*
*working*
                                                 (Final Answer)

Or do you have to say:

the string is 1337cm.                     (Final Answer)

Or
                                          (Final Answer)


4. How do you justify that is the max/min/stat point of inflexion of if is filled with unknowns e.g.
 (or is that unreasonable)

Add more when i think of them, thanks!

[Glockmeister]

1. Provided the examiner can follow where your work is going, it should be ok

2. Apparently that is the 'proper' notation, according to Mao and Associates. Kilbraha seem to love that notation.

3. I don't think examiners will care that much to be honest, although you should put the units as part of the final answer, so that the assessor doesn't miss it.

4. Don't get what you're saying to be honest.

[plato]

1.  Write wherever you like as long as the marker is able to read and follow your logic and find your answer. You can write on the back cover if need be as long as you put a pointer to your answer or its continuation near the actual question.

2.  I suggest you do not use this notation. Your marker may not be familiar with it and you could lose out.

3.  Strictly, an answer of "the string is 1337 cm" is incorrect as it is the "length of the string" that is 1337 cm but I don't believe they will be that pedantic.
If the question asks for a length, then give the answer as Length = 1337 cm
If the question asks for the value of x, then x = 1337 is adequate but I suggest you could still add cm to this answer.
If you have invented x to stand for the length, then define it so that your working can be followed. Then I would still write the answer as Length = 1337 cm rather than x = 1337 cm

4.  I think a question with such a complicated function would be unreasonable .

[/0]

k thanks  glockmeister and plato

btw glockmeister what I meant is, if you have a function with lots of unknown constants, then if you try to make a sign diagram, then you won't know when it is negative and when it is positive.

[Glockmeister]

yeah you won't get that question in the exams.

[Mao]

k thanks  glockmeister and plato

btw glockmeister what I meant is, if you have a function with lots of unknown constants, then if you try to make a sign diagram, then you won't know when it is negative and when it is positive.

if you absolutely have to, you can make a few assumptions and work out a few scenarios. e.g. for that question, you may take a to be one of three categories: (0,1) [decreasing], 1 [constant], >1 [increasing], and then work out a possible range of accepted values for certain behaviours of y at x=p.

but you won't be asked that on the exam

[shinny]

I've seen variations of that kind of question and often it'll take a bit of inequality work to prove what you want. But generally, I heavily doubt you'll be asked that.

[kurrymuncher]

Can someone clear up this defining thing. Ive never been told to do it at school.
Do they take marks of if you dont define something?

[/0]

Can someone clear up this defining thing. Ive never been told to do it at school.
Do they marks of if you dont define something?

Dunno, but it is always safe to define any new variable you use. You'll need to do this most often with probability questions (and barely ever with other questions). Make sure you say something like for normal distributions and for binomial.

________________________________________________________________________________________________________________________________

Ok I'm thoroughly pissed off at the hypocrisy of VCAA solutions. They BARELY EVER justify their stationary points!!11

To see examples of this, check out VCAA 2007 Exam 2 Question 1 Part d, Question 3 Part a, Question 3 part c, Question 5 part f) i) (3 LINES?!?! WTF IT TAKES ME 3 LINES JUST TO JUSTIFY A STATIONARY POINT LET ALONE DO THE QUESTION AND GIVE THE ANSWER)

!!! :tickedoff: !!!

Am I allowed to do that what they're doing?

If you have a question that is worth two marks and there are 2 answers, do you need to show working for meth marks? What about these FRIGGIN stationary points gaah they piss me off so much. Sometimes I feel like I'm doing too much working cuz I have to fill up all the lines on every question to get what I mean across, I would love to leave stuff out if they didn't punish me for it.

THANKYOU

/endrant

[nerd]

Generally, do you have to prove that a stationary point is a minimum/maximum with a sign diagram, if it does state to do so in the question?

[plato]

Unless specifically asked to do so, you do not have to prove that you have a maximum or minimum. Just simply state the maximum (or minimum or stationary point of inflection) occurs at gradient = zero

[/0]

Unless specifically asked to do so, you do not have to prove that you have a maximum or minimum. Just simply state the maximum (or minimum or stationary point of inflection) occurs at gradient = zero

I thought it was expected for you to always justify. In fact, in some questions, they say "You are not required to justify the nature of the stationary point", which I think implies that at all OTHER times, you must.

I hope you're right though, it would be a lot easier...

[trinon]

Unless specifically asked to do so, you do not have to prove that you have a maximum or minimum. Just simply state the maximum (or minimum or stationary point of inflection) occurs at gradient = zero

I thought it was expected for you to always justify. In fact, in some questions, they say "You are not required to justify the nature of the stationary point", which I think implies that at all OTHER times, you must.

I hope you're right though, it would be a lot easier...

No, you only ever have to justify the type of stationary point if the question asks it. VCAA will specifically ask on the exam if they want it or not.