VCE Methods Question Thread!

[strawberries]

Question 4 of 2012 VCAA Exam 2

Given that g is a differentiable function and k is a real number, the derivative of the composite function g(e^(kx)) is:

The answer is:
kg'(e^(kx))e^(kx)

but I don't get how?

I always get confused on questions like this

bump


I have another question - 2011 VCAA Exam 1 Question 7 a ii

A biased coin is tossed 3 times. The probability of a head from a toss of this coin is p.
Find in terms of p, the probability of obtaining

2 heads and 1 tail from the 3 tosses

the answer is (3p^2)(1-p)

but shouldn't it be (p^2)(1-p) because you multiply p twice?

[keltingmeith]

quick question: for the exam, if we were to do separate working out to check our answers - do u think it'd be okay? is it not recommended or..?

You can do it, definitely okay and I'd suggest doing it if you have time. If you don't want the examiners to read what you've done, just cross it out.

[keltingmeith]

bump


I have another question - 2011 VCAA Exam 1 Question 7 a ii

A biased coin is tossed 3 times. The probability of a head from a toss of this coin is p.
Find in terms of p, the probability of obtaining

2 heads and 1 tail from the 3 tosses

the answer is (3p^2)(1-p)

but shouldn't it be (p^2)(1-p) because you multiply p twice?

First one:

Let , then:



Second one:

Coin flip, probability of heads is p, flip three times. So, if we call the outcome of getting heads X, , so:

[IndefatigableLover]

quick question: for the exam, if we were to do separate working out to check our answers - do u think it'd be okay? is it not recommended or..?

I wouldn't suggest it as to what (I'd follow what EulerFan101 said above.) For me I did working out separately before writing my final answer in a SAC at school once and I was heavily pressed for time and it was just the worst experience LOL
Though at most what you could do is to rip out the detachable formula sheet and use that as working out paper if you run out for example

EDIT: Just re-read what I wrote and it is completely misleading LOL (sorry about that EulerFan101)!

[keltingmeith]

I wouldn't suggest it as to what EulerFan101 said above. For me I did working out separately before writing my final answer in a SAC at school once and I was heavily pressed for time and it was just the worst experience LOL
Though at most what you could do is to rip out the detachable formula sheet and use that as working out paper if you run out for example

Should possibly clarify - ONLY follow my advice if you have time at the end (after doing all the questions, first) AND if it won't make your answer illegible. Invigilators should be able to supply you with spare paper for rough working if you ask, though.

[Edward Elric]

For 2008 exam 1 vcaa, why is the domain of f(f^-1(x)) restricted from (-1,infinity)?

[keltingmeith]

For 2008 exam 1 vcaa, why is the domain of f(f^-1(x)) restricted from (-1,infinity)?

Because that's the domain the inner function (the inverse) is defined for.

[Jason12]

for circular functions, if we start with x element of [0, pi] and we have (x/2) do we change the domain by dividing all the values in the domain by 2? i.e. (x/2) is an element of [0. pi/2]

[Reus]

Thanks so much euler!!! I get it know (you should be a teacher  )
I feel confident with exam 1 but not exam 2 but oh well... one thing at a time

[soNasty]

the last question for the 2011 methods exam 1 VCAA was a joke.
Anyone care to explain what theyre even asking and how to go abouts in solving it?
(if you can be bothered)

[strawberries]

First one:

Let , then:



Second one:

Coin flip, probability of heads is p, flip three times. So, if we call the outcome of getting heads X, , so:

thanks for Q1!

I still don't get with the second question though (sorry I'm dumb)

[jw12]

the last question for the 2011 methods exam 1 VCAA was a joke.
Anyone care to explain what theyre even asking and how to go abouts in solving it?
(if you can be bothered)

Max when derivative equals zero, so from the last part you know that BD = 2CD, so using Pythagoras you can figure BD out and then add all the sides together. I'm sorry if that makes no sense I'm horrible at explaining ahah

[keltingmeith]

for circular functions, if we start with x element of [0, pi] and we have (x/2) do we change the domain by dividing all the values in the domain by 2? i.e. (x/2) is an element of [0. pi/2]

Yep, that's good.

thanks for Q1!

I still don't get with the second question though (sorry I'm dumb)

Alright - at this point, you don't have the time to learn binomial, so think of it this way:

You have three options - either you get THH, HTH, HHT. These are the three different scenarios of getting 2 heads and 1 tails (which is what we're looking for).

Adding the probabilities of each up (each have probability of occuring), we get .

[Sam_4331]

Where and when will answers be posted for exam1?

[myanacondadont]

Assuming a relatively similar difficult as last year what ss could I expect with:
Sac's: 90/100
GA1: 35/40 or 34/40
GA2: 63/80   Thanks ^.^