VCE Methods Question Thread!

[knightrider]

Methods does not explictly assess matrix arithmetic (7A and 7B), however knowledge of it is very useful for when you use matrices (transformations and markov chains). 7C shouldn't be required, but it's still handy to know (just in case). 7D would be a very important exercise.

Tl;dr, I'd do all of them, but 7C isn't that big a deal.

On Markov chains and transition matrices - your school is stupid to skip this (welp, maybe not, I don't know the teacher's/classes situation). Holy crap are these important (and difficult to understand for most). I would highly recommend going over them over the holidays.

Thanks so so much EulerFan101

[Orb]

Hey guys,

A quick question when sketching graphs:

If the maximal domain is R, with my graphs that extend past the end point of the allocated area I place an arrow to signal that it still continues.

Will marks be deduced for 1) Having it or 2) Not having it

Thanks!

[silverpixeli]

Hey guys,

A quick question when sketching graphs:

If the maximal domain is R, with my graphs that extend past the end point of the allocated area I place an arrow to signal that it still continues.

Will marks be deduced for 1) Having it or 2) Not having it

Thanks!

Both are fine in my opinion, I think graphs without the arrow look a little nicer. The kind of thinks you lose marks for in this situation would be incorrectly making it look like an endpoint (like by making it a dot) or making it curl the wrong way/touch an asymptote or something like that. If you draw the line as if the graph was just cut off where the area ends, you're fine!

[IndefatigableLover]

Quick question in writing on the exam, so I was working through VCAA 2009, Exam 1 - Question 1b. and when I was working through the question I had a problem... so the amount of lines that were given on the exam wasn't enough for me to fully write my answer in (I had to go all the way to the bottom of the page) but if I were to go over the lines, would that still be okay? I'm just paranoid in terms of what they'll take as my answer in the end since I'm going over the lines (just happens to be that one question so far)...

[keltingmeith]

Quick question in writing on the exam, so I was working through VCAA 2009, Exam 1 - Question 1b. and when I was working through the question I had a problem... so the amount of lines that were given on the exam wasn't enough for me to fully write my answer in (I had to go all the way to the bottom of the page) but if I were to go over the lines, would that still be okay? I'm just paranoid in terms of what they'll take as my answer in the end since I'm going over the lines (just happens to be that one question so far)...

If it's legible, you should be fine.

[jw12]

Is the domain of a composite function always the domain of the inside function? Thanks in advance!

[keltingmeith]

Is the domain of a composite function always the domain of the inside function? Thanks in advance!

As far as methods is concerned, this is ALWAYS the case. If you continue on to maths in university (particularly computer science), this isn't always the case, so watch out then.

The reason this is always the case for methods is that methods says a composition for f(g(x)) only exists if range(g) domain(f). If this is true, then the domain for f(g(x)) is equal to the domain of g(x).

[lzxnl]

As far as methods is concerned, this is ALWAYS the case. If you continue on to maths in university (particularly computer science), this isn't always the case, so watch out then.

The reason this is always the case for methods is that methods says a composition for f(g(x)) only exists if range(g) domain(f). If this is true, then the domain for f(g(x)) is equal to the domain of g(x).

No, it's not ALWAYS the case because the counterexample you've provided appears in VCE too.

Simple example: composition of x^2-1 and sqrt x? sqrt(x^2 - 1) can't be defined for all real x

[Orb]

Quick question in writing on the exam, so I was working through VCAA 2009, Exam 1 - Question 1b. and when I was working through the question I had a problem... so the amount of lines that were given on the exam wasn't enough for me to fully write my answer in (I had to go all the way to the bottom of the page) but if I were to go over the lines, would that still be okay? I'm just paranoid in terms of what they'll take as my answer in the end since I'm going over the lines (just happens to be that one question so far)...

Maybe try expressing the fractions within one line?
I did that way and ended up with around 2 lines spare for that same question

[IndefatigableLover]

Maybe try expressing the fractions within one line?
I did that way and ended up with around 2 lines spare for that same question

I dunno.. my writing gets really small and all when I bunch things up like that... it just took a while for me when I subbed in and just simplified it all the way showing each step 

[keltingmeith]

No, it's not ALWAYS the case because the counterexample you've provided appears in VCE too.

Simple example: composition of x^2-1 and sqrt x? sqrt(x^2 - 1) can't be defined for all real x

However, as far as VCE is concerned, that isn't a valid composition, since range(x^2 -1)domain(sqrt(x)). So, my logic holds true.

[myanacondadont]

No, it's not ALWAYS the case because the counterexample you've provided appears in VCE too.

Simple example: composition of x^2-1 and sqrt x? sqrt(x^2 - 1) can't be defined for all real x

What are the chances. Just did a question like this - VCAA 2011 Exam 1 Q4b. How would you go about defining the domain in this case?

[lzxnl]

You just want when the range of x^2 - 1 fits into the domain of sqrt x
It makes sense if you think about it; sqrt(x^2 - 1) has x^2 - 1 under a square root, so whatever comes out of x^2 - 1 has to go into a square root.

[knightrider]

HI lzxnl,

I have a question for you.
i was reading your previous posts and you said that your school initially entered your sac scores as an A and your study score went down to 46.

How did you get this problem fixed and also how did you know that your school entered your results wrong.

[keltingmeith]

What are the chances. Just did a question like this - VCAA 2011 Exam 1 Q4b. How would you go about defining the domain in this case?

Whoops, looks like my information was wrong - I had been made aware that VCAA didn't do this.

Apologies, lzxnl - I take my comment from before back.