VCE General & Further Maths Question Thread!

[mtDNA]

Could someone please explain how to do question 9 bii (finance) from the 2016 Sample exam? I’ve seen solutions with different answers, so I just wanted to check if my working is correct 

[Maggies]

Can someone please explain Permutation/transpose matrices to me?

[BlinkieBill]

Hey,
if we are to write down a matrix and the elements represent prices, do we have to write it to 2dp??
i got a 2x1 column matrix where one element is an integer and the other is an exact decimal

[BlinkieBill]

How do you answer - interpret the standard score?
from further 2016 sample exam Q5bii

[blood]

Can anyone help me to work out this question and show how they worked it out please.

' Kuong invests $8500 at 6% interest per annum, compounding quaterly. The amount of interest he earns during the fourth year of investment is?

P.S the answer is $623.63 but not sure how it is worked out.

Thanks

Mod edit: Post restored. Please do not delete a question after it has been answered.

[BlinkieBill]

Can anyone help me to work out this question and show how they worked it out please.
' Kuong invests $8500 at 6% interest per annum, compounding quaterly. The amount of interest he earns during the fourth year of investment is?
P.S the answer is $623.63 but not sure how it is worked out.
Thanks

Hey i plugged all this into my financial solver.
For N=12 (after 3 years) I got FV= 10162.75
N=16 (after four years) I got FV= 10786.38
Then i subtracted and got 623.23 - you can subtract since there are no additions or payments

Mod edit: Post restored.

[Aaron]

Can anyone help me to work out this question and show how they worked it out please.

' Kuong invests $8500 at 6% interest per annum, compounding quaterly. The amount of interest he earns during the fourth year of investment is?

P.S the answer is $623.63 but not sure how it is worked out.

Thanks

This is how i'd work it out.. obviously there may be an easier way. You want to find out how much interest is earned over the 4th year of the investment.

4 years, compounding quarterly: 8500(1+(0.06/4))^16 = $10786.377 (future value after the 4th year, rounded)
3 years, compounding quarterly: 8500(1+(0.06/4))^12 = $10162.754 (future value after the 3rd year, rounded)

difference: 10786.377 - 10162.754 = approx 623.623

Edit: same as BlinkieBill's... i'll keep mine since it shows the formula if you were to do by hand

[blood]

This is how i'd work it out.. obviously there may be an easier way. You want to find out how much interest is earned over the 4th year of the investment.

4 years, compounding quarterly: 8500(1+(0.06/4))^16 = $10786.377 (future value after the 4th year, rounded)
3 years, compounding quarterly: 8500(1+(0.06/4))^12 = $10162.754 (future value after the 3rd year, rounded)

difference: 10786.377 - 10162.754 = approx 623.623

Edit: same as BlinkieBill's... i'll keep mine since it shows the formula if you were to do by hand

Hey i plugged all this into my financial solver.
For N=12 (after 3 years) I got FV= 10162.75
N=16 (after four years) I got FV= 10786.38
Then i subtracted and got 623.23 - you can subtract since there are no additions or payments

Mod edit: Post restored.

Thanks both

[BlinkieBill]

Hey
how important are units in further?
do we get marks taken off for not writing them??

[blood]

Can any help with this questions, please

The value of of the car could also be depreciated using reducing balance depreciation.
Using the this method, the value Vn, in dollars, of the car after n years would be modelled by the recurrence relation
Vo = 28000 Vn+1= 0.29Vn
After how many years would the car first have a value less than $10,000?

I can do it on the casio classpad in sequence but what working out would you do?

Thanks

[Steve252]

Hey
how important are units in further?
do we get marks taken off for not writing them??

I think just like Methods and Specialist, missing units will only cost you 1 mark irrespective of how many times you forget them
And they definitely matter, as such small details split the top students.

[dec.hargreaves]

Can any help with this questions, please

The value of of the car could also be depreciated using reducing balance depreciation.
Using the this method, the value Vn, in dollars, of the car after n years would be modelled by the recurrence relation
Vo = 28000 Vn+1= 0.29Vn
After how many years would the car first have a value less than $10,000?

I can do it on the casio classpad in sequence but what working out would you do?

Thanks

I would usually say "after x amount of years the value of the car is y"
could be different

[AngelWings]

Matrices Help

Can someone please explain Permutation/transpose matrices to me?

I don't remember much of this, but I definitely remember it was also covered in Methods. Would recommend you look for some Methods resources or check out this Khan Academy link for transpose matrices and this Wolfram Alpha link for permutation matrices. Sorry that I'm not super helpful here.

if we are to write down a matrix and the elements represent prices, do we have to write it to 2dp??
i got a 2x1 column matrix where one element is an integer and the other is an exact decimal

If it represents prices, just enough zeroes to give 2dp. It's easier to see a price in 2dp because we work with cents and they'll probably ask you to round to it anyway. Same goes with integer dollars, unless otherwise stated.

How do you answer - interpret the standard score?
from further 2016 sample exam Q5bii

Sample Exam 2016 E2 Core Question 5bii

The question is as follows:

Interpret the z-score of this suburb’s population density with reference to the mean population
density.

I would write a sentence like "This suburb's population density was relatively [higher/ lower] than the mean population density, with a [positive/negative] z score of [insert z score here]. This indicates that [more/ less] people live in this suburb per square kilometre."
Remember: positive z score = this suburb > mean, negative z score = this suburb < mean, (z = 0) = this suburb = mean.

Financial and Recursions Help

I can do it on the casio classpad in sequence but what working out would you do?

I would usually say "after x amount of years the value of the car is y"
could be different

What I used to do was write up a line of the equation I used and the numbers I originally substituted with.
Then, I'd add a small table with two columns with what a few of the n (n= 1, 2, draw a few dots, [insert number before answer and answer]) and V_n values were.
Then, I'd write down one last line with the actual answer underneath that.
This was mostly for the Number Patterns module, which existed before the change in 2016, but should be similar in Financial Maths and Recursions.
Dec.Hargreaves might be right since my knowledge is outdated.

[elle6299]

Hey, I was just wondering if someone could help me on how I would go about this question (geometry and measurement)!

'Two similar cones of radius 4 cm and r cm (smaller than the first) are shown below.
The volume of the larger cone is three times the volume of the smaller cone.
The value of r is closest to...'
Options are 0.8 (A), 1.9 (B), 2.1 (C), 2.5 (D), and 2.8 (E).

Thankyou in advance!!

[Shaqattack]

when drawing a regression line, what do vcca look for.?
Is it enough to get 2 points on the graph accurate from the equation present or does the line need to go through specific points?