VCE Methods Question Thread!

[sandrab]

can someone please help me with question 8 in the 2009 exam 1
and
10b in the 2012 exam 1  thanks

[Robert123]

can someone please help me with question 8 in the 2009 exam 1

F(x)=e^x+ k
F(a)=e^a+k
F'(x)=e^x
So we know the tangent at point a goes through the origin.
F'(a)=e^a=m
So that is the gradient of the tangent, now using the coord (0,0) and the tangent formula we get
y-y1=m(x-x1)
Y=x*e^a
So that is the equation of the tangent, subbing in the coordinates for (a,e^a+k) we get
E^a+k=a*e^a
K=a*e^a-e^a
Does that clarify it for you?

[kawfee]

For Linear approx.
How would be answer/work out 'Explain why this approximate value is greater than the exact value for ___'

?

Thank you.

[soNasty]

How does one set out their working in an exam?
For each lime, do you add an equals sign and continue working down?

[IndefatigableLover]

How does one set out their working in an exam?
For each lime, do you add an equals sign and continue working down?

Generally for Exam 1's what I tend to do is split up the answer lines into two columns and work down one before drawing an arrow to go to the next column before I mark my final answer with a double slash
Most of the time I do tend to use the equals sign down all the way plus the 'therefore' sign at the start of my equation before I do anything to it.

[chocolatechipcookies]

this is probably the dumbest question of all, but Q8 on 2013 VCAA exam 1?

I really don't get how to incorporate the "given that d/dx" blah blah

Can I just solve it without knowing the 'given that'?

[silverpixeli]

this is probably the dumbest question of all, but Q8 on 2013 VCAA exam 1?

I really don't get how to incorporate the "given that d/dx" blah blah

Can I just solve it without knowing the 'given that'?

It's an integration by recognition question, so you need to use the "given that d/dx something = something else" information (actually the reverse relationship that says something = integral (something else)) in your working to be awarded full marks. iirc it's a function like xcos(x) or something which can't be solved with Methods integration techniques (though there are techniques outside of the course that would do it) so yeah, you need to use the information given to arrive at an answer

[Valyria]

Hey,

How do you guys indicate which line is your final answer? Double diagonal slash or?

[silverpixeli]

Hey,

How do you guys indicate which line is your final answer? Double diagonal slash or?

I normally wrote in black pen and then underlined in blue,
You could also put a box around it,
Just putting it at the bottom of the page is fine too

[soNasty]

This is my working for some questions in the 2012 exam 2.
The answers are correct, but would I get full marks?

[silverpixeli]

This is my working for some questions in the 2012 exam 2.
The answers are correct, but would I get full marks?

Perfect

[Valyria]

Hi,

Just completed the MAV 2013 exam 2 and a question cropped up;

When we are required to find the range between which 95% of the distribution lies, do we have to use mean +/- 2 standard deviations? Since  I thought that was an approximation, I actually performed normCDF calculations but my answer was different to the suggested solutions.

[soNasty]

Perfect

Alright awesome thanks !!

[silverpixeli]

Hi,

Just completed the MAV 2013 exam 2 and a question cropped up;

When we are required to find the range between which 95% of the distribution lies, do we have to use mean +/- 2 standard deviations? Since  I thought that was an approximation, I actually performed normCDF calculations but my answer was different to the suggested solutions.

Good question, in my opinion both approaches are okay unless it specifically asks you to use the 68-95-99.7 rule or otherwise. On a tech free, you obviously need to rely on the rule. If anyone knows of a VCAA paper and assessment report that says one method is preferred, let us know, otherwise I can't imagine they'd take a mark off you for giving a slightly more accurate answer than the rule provides.

[cwiddicombe]

Question - if they ask to find the inverse of a function, should you always answer it in function notation (including its domain)?