VCE Methods Question Thread!

[Billuminati]

Hi All,

Can someone please help me w/ q9 a?

Much appreciated,
beep boop

I'm usually rubbish at maths but I'll attempt to answer anyways (see attached screenshot)

[PizzaMaster]

Heyy guys,
If we have a question like
x^3 + 5x -10 has only one solution.
The solution lies between what (0 and 1, 1 and 2 etc.) ?
Do we solve it using a calculator and see what the graph looks like, but what if we are not allowed a CAS?

I have just another question
If a question says to find the maximum deviation from x-axis of a cubic graph ie. the height.
Can the deviation mean from both positive and negative side (maximum or minimum).


Thank you!!

[hvo-ade]

For the type of question 1, you probably need to use the rational root theorem and/or bisector method. If the equation have a rational root, definitely use the rational roots theorem after using bisector method to locate the possible interval.
For question 2, deviation means both sides.

[beep boop]

Hi All,

Can someone please help me with the highlighted parts? I thought for q9 splitting them would work but I couldn't find the right answer. For q10, I found the tangent at the negative x intercept but then I got stuck.

Much appreciated,
beep boop

[TnGn74]

Hi beep boop,
I think that you have the right idea for q9.
\[ \int_1^6(f(x)+1)dx = \int_1^4f(x)dx + \int_4^6f(x)dx + \int_1^61dx \]
Question 10 appears to be incompletely copied from the 2021 NHT exam and should read 

The tangent to the graph of f is parallel to the line connecting the negative x-intercept and the y-intercept of f when x is equal to

Hope that helps!

[PizzaMaster]

Hi guys
If a question says:
Write the answer in nearest cm, when the units are in metres.
Does to the "nearest cm" mean to write the answer in cm or could it be metres .(decimal) -- cm.
For example something like:
Y = x-1
Where x in metres
But then the answer says to "nearest cm"
can I write, for example, 3.45 metres
where the .45 is the "nearest cm"?

Thank you!

[james.358]

can I write, for example, 3.45 metres
where the .45 is the "nearest cm"?

Yep! This is exactly how you should do it. I know it might seem confusing, but it is the equivalent of the question asking you to "give your answers correct to 2 decimal places, in meters"

[ihavenolife:(]

Hey guys

Needed some help with this question

a) Find the derivative of x²e^kx

b) Hence find an anti-derivative of xe^kx


I tried using Integration by Recognition on this question, since this is the only method my teacher will teach, but could never get the right answer. I sorta got stuck in a loop where to find one of the integrals I needed to find the integral of the other one.

Was wondering if any of you guys knew how to do it?

Thanks

[1729]

Hey guys

Needed some help with this question

a) Find the derivative of x²e^kx

b) Hence find an anti-derivative of xe^kx


I tried using Integration by Recognition on this question, since this is the only method my teacher will teach, but could never get the right answer. I sorta got stuck in a loop where to find one of the integrals I needed to find the integral of the other one.

Was wondering if any of you guys knew how to do it?

Thanks

Hi, ialsohavenolife! 

Thank you very much for posting your working out, and good job on attempting the question!

As far as I can see, there is absolutely no issue with your working out and it's actually unsolvable in the scope of VCE Methods.

To be able to solve this you would need to know what \(\int \:x^2e^{kx}dx\), which you do not know (as you pointed out).

EDIT: Response below is better, and is in the scope of methods, however, the question mentioned 'hence' which is why I didn't go with that approach, although it's valid.

[hvo-ade]

That's how I did it. But it should not be in the study design for MM and even it posed a tricky question for Specialist. Maybe next year when proof would have more weight in the new SD.

[beep boop]

Hi All,

Can someone please help me with the highlighted parts?

Much appreciated,
beep boop

[Billuminati]

Hi All,

Can someone please help me with the highlighted parts?

Much appreciated,
beep boop

Q7: Set up 2 simultaneous equations using relevant probability formulas and solve for the 2 unknown probabilities
5/6 = 1/3 + Pr(B) - Pr(A n B)
3/4 = Pr(A n B) / Pr(B)
A and B are independent events only if Pr(A n B) = Pr(A) * Pr(B)

Q8: Do a Karnaugh map aka two way probability table for this one

[tiredandstressed]

My methods is a little rusty but I think this might be the working for Q8
*Please correct if wrong*

[beep boop]

Hi All,

Can someone please help me with q29 part a?

I'm kinda confused as to what to put on the tree diagram bc 1/3 and 5/9 doesn't add up to 1.

Much appreciated,
beep boop

[james.358]

Love to help but attachment says "404 - attachment not found" when I try to open it.

Not sure if it's just me?