VCE Methods Question Thread!

[SS1314]

Hi there, im a little confused about a line of working - i've attached it to this pls send help
for the step where 14=8x 2^-b - 2^-b (line 3), how does it simplify to 14= 7 x 2^-b? what happens to the -2^-b?
many thanks 

Should imagine the third line as being composed of fractions. So 2^-b becoming 1 over 2^b and 8x2^-b becoming 8 over 2^b. It will be clear after that.

[moonchild]

Hope that helps!

Should imagine the third line as being composed of fractions. So 2^-b becoming 1 over 2^b and 8x2^-b becoming 8 over 2^b. It will be clear after that.

thanks heaps, really appreciate it

[TheEagle]

Hey guys

I am having trouble understanding if I need to keep sketches of the individual graphs.
The question is: sketch y= (x^4 + 2) / x^2

I have so far simplified it to: y=x^2 + 2/x^2

I then drew x^2 and 2/x^2 on the same axis

From the individual graphs, I have done addition of ordinates and have successfully drawn the expected graph, however, in the answer, they do not include y=x^2 and y=2/x^2 as asymptotes.

I have attached the graph which I got on my book as well as the final answer the book has (marked red)

[TheEagle]

What I got:

[S_R_K]

Hey guys

I am having trouble understanding if I need to keep sketches of the individual graphs.
The question is: sketch y= (x^4 + 2) / x^2

I have so far simplified it to: y=x^2 + 2/x^2

I then drew x^2 and 2/x^2 on the same axis

From the individual graphs, I have done addition of ordinates and have successfully drawn the expected graph, however, in the answer, they do not include y=x^2 and y=2/x^2 as asymptotes.

I have attached the graph which I got on my book as well as the final answer the book has (marked red)

\(y=\frac{2}{x^2}\) is not an asymptote to this graph.

You can leave in your drawings of \(y=\frac{2}{x^2}\) and \(y=x^2\) as dotted lines to indicate they are just there as "guiding curves" to help with addition of ordinates. But they are not required.

Also, in Methods, you are not expected to indicate asymptotic behaviour that is anything other than a vertical / horizontal line.

[statistics]

2.2 What’s the design? Read the brief description related to a statistical study below, and
 a) explain why it is an experiment rather than an observational study.
Runners recovering from lower leg fractures were randomly allocated to three
different training programs. Half of each group also followed a high calcium diet.
Bone density measurements were taken for all subjects.
Also:
b) identify the factor(s) in the experiment and the number of levels for each.
c) give the total number of treatments.
d) state the response variable(s) measured.
e) explain whether it was blind, or double-blind

2.3 Some studies suggest that having a pet can provide positive mental and physical health benefits for the owner.
A particular study involving elderly people who lived alone reported that dog owners had lower blood pressure on
average than the non dog-owners, with the difference in average blood pressure between the groups statistically
significant.
a) In this context, what does “statistically significant” mean?
b) Explain why this study would be an observational study rather than an experiment.
c) Does this result mean that if an elderly person buys a dog that their blood pressure will decrease? Explain.
d) Suggest some possible associated confounding variables for this study.

Can I please have help with these questions??
I'm not sure how to do any of them
Thanks

[dunno2012]

Hello, I just wanna know roughly how many marks can u lose on the exam to get a 48 in methods

[darkz]

Hello, I just wanna know roughly how many marks can u lose on the exam to get a 48 in methods

Varies from year to year, but I scored 92.5/100 to score a 48. (A very forgiving year if you ask me)

[Bri MT]

For the following statement about a statistical survey, identify the following items (if possible). If you can’t tell,
then say so – this often happens when we hear or read about a survey.
A recent online poll conducted by an Australian newspaper of 1083 registered voters found
 that 43% of the respondents believe it is likely that bushfires are linked to climate change

a) The possible population of interest
Registered voters
b) The population parameter
proportion of registered voters who believe it's likely that bushfires are linked to climate change
c) The sampling frame
1083 registered voters
d) The sample
43% of 1083
e) The sampling method, including whether or not randomisation was employed
voluntary response survey, randomization is NOT used
f) Who (if anyone) was left out of the study
people who didn't vote and people who didn't participate in the survey
g) Any potential sources of bias you can detect and any problems you see in generalising to the population of
interest
people are more likely to participate in the survey if they have a strong opinion towards either side
Can you please tell me if my answers are correct? Be as harsh as you can
And yes, this is 1st year uni maths, and I don't have a textbook why is why i'm having trouble with these questions
Thanks

I'm moving this to the uni section. All related posts can now be found here

[dunno2012]

Varies from year to year, but I scored 92.5/100 to score a 48. (A very forgiving year if you ask me)

Thanks sm, what did u get for like exam 1 and 2 specifically btw (if u don't mind sharing)

[Sine]

Thanks sm, what did u get for like exam 1 and 2 specifically btw (if u don't mind sharing)

Not darkz but in general for a 48 in methods you can drop anywhere between 2.5 and 6 marks across both exams depending on the difficulty for 48 in most years.

There are probably a few outlier years though.

[Brydie.engell]

a)      Find rational factors for x^3+2x^2-x-2 without using your CAS.

b)      Hence solve  x^3+2x^2-x-2 > 0

How do you do part b?

[Evolio]

Hey, well since you found the factors, then you should be able to sketch the graph as the linear factors can be used to find the x intercepts. The second question is asking you which parts of the expression is above 0 so you can sketch your graph and then find the x values where the y values are above 0 (y value of 0 that is ), not including the x intercepts of course.

Which specific part were you unsure about, by the way?

[Snow Leopard]

Hi,
For the example I've attached, would you sub in (3,2) as 2 = a(3+1)(3-2)^2
Thanks in advance!

[Evolio]

Yes.