VCE Methods Question Thread!

[shadows]

I think you're a little confused with your terms;

(relates to square matrices)

(relates to the roots of a polynomial)

Oh yes! Always get the 2 mixed up!

Great pick up! Thanks .

[Alwin]

I think you're a little confused with your terms;

(relates to square matrices)

(relates to the roots of a polynomial)

THANK!! great pick up, I didn't know how to do the triangle sign thingo in LaTeX so just decided to type it in... look where it got me haha. I was just thinking of determinants from the previous question in this thread..

Also, just quickly how do I do a greater and equal to sign.. I though >= would do the trick but apparently not.
Thanks!

[Phy124]

Oh yes! Always get the 2 mixed up!

Great pick up! Thanks .

THANK!! great pick up, I didn't know how to do the triangle sign thingo in LaTeX so just decided to type it in... look where it got me haha. I was just thinking of determinants from the previous question in this thread..

Also, just quickly how do I do a greater and equal to sign.. I though >= would do the trick but apparently not.
Thanks!

No worries 

Code: [Select]

\leq

Code: [Select]

\geq


Here's a nifty little editor which can be helpful when learning latex: http://www.codecogs.com/latex/eqneditor.php

[Alwin]

No worries 

Here's a nifty little editor which can be helpful when learning latex: http://www.codecogs.com/latex/eqneditor.php

Oh thanks! you're too kind

[Chazef]

I'm currently using the maths quest textbook and it has a HUGE amount of questions (like all maths books), often with little variation between sub-questions (a,b,c etc). I've always taken the question-spam approach to maths just because I assumed the textbook had all those questions for a good reason; 'spamming is the only way to get efficient'. But now I'm starting to wonder whether there's much point doing any more than 2 or 3 subquestions for each question in the book, because other textbooks don't have nearly as many questions (e.g. physics) and I can manage to get a good grip of the knowledge of chapters just by doing those questions. So anyway, does maths require a larger level of question-spamming than other subjects to become proficient like the textbook suggests, or is all that extra time spent doing similar questions going to waste? Thanks in advance for any responses

[Alwin]

I'm currently using the maths quest textbook and it has a HUGE amount of questions (like all maths books), often with little variation between sub-questions (a,b,c etc). I've always taken the question-spam approach to maths just because I assumed the textbook had all those questions for a good reason; 'spamming is the only way to get efficient'. But now I'm starting to wonder whether there's much point doing any more than 2 or 3 subquestions for each question in the book, because other textbooks don't have nearly as many questions (e.g. physics) and I can manage to get a good grip of the knowledge of chapters just by doing those questions. So anyway, does maths require a larger level of question-spamming than other subjects to become proficient like the textbook suggests, or is all that extra time spent doing similar questions going to waste? Thanks in advance for any responses

haha not really in my opinion. Understanding it often key in maths, repetition is to make sure you keep on understanding correctly. If you find yourself bored or an exercise repetitive, do the first few qs then "spam" they last ones of the exercise going in reverse order until you reach the questions you can easily do / find repetitive. Also, I just recommend you do checkpoints (PREFERABLY A PRE 2013 ONE) along with your textbook qs. Although, I actually finished my checkpoints book before the year started, but that's just one way to approach the course.

Good luck with your studies this year!

[justsoundslikeaworn-outcliche]

Okay I've found that I can do regular question quite easily, but I often have trouble when they are written as a problem :? The wording just makes me lose my footing 
ANYways

Need urgent help with these questions: (for a practice SAC)
There is no wind at 1pm, and at 3pm there is 200km winds (cyclone)
1) Graph linear model. Let t equal time after noon, and v equal wind speed. Establish linear model of the form v=at+b
B) Why is this unsatisfactory  to model a cyclone's behaviour?

2) Wind speed peaks at 256km/h at 5pm. Use data+speed at 1pm to create quadratic model?
b) the wind speed returns to zero at 1am the following morning. 12 hours later. Discuss how well this results matches quadratic model.

[justsoundslikeaworn-outcliche]

^for 1a) the eq I found was v=100t-100 but I dunno

[Zealous]

Create a linear model.
Let t = 1 be 1pm, t = 2 be 2pm, t = 3 be 3pm and so on.

So you have two points, you know the wind which we will call v, is 0 at 1pm and 200km at 3pm.

and
Find the gradient, which is rise/run, which is 100.

Sub into
(in this case y is v and x is t)




Wind speed peaks at 256km/h at 5pm, as it is a peak, it will be a turning point on a quadratic.

So now you have 3 points, (1,0), (3,200) and (5,256) which you can easily sub all those into the standard quadratic form of


[EDIT] see Laserblued's post, I was a little off in my equation, use turning point form instead.

Spoiler

I used my calculator quickly to create the quadratic equation which I believe is:

(can someone check that please?)

[Lasercookie]

I used my calculator quickly to create the quadratic equation which I believe is:

(can someone check that please?)

Whilst it does match up to the coordinates of (1,0) and (5,256), the turning point for that parabola isn't (5,256).

General form of the quadratic equation This one is good because we know that (h,k) will be the turning point, and saves us some effort with the algebra. (5,256) is it's peak, so this must be a negative quadratic.


Subbing in (1,0)


Which gives which expands to

[shadows]

Hey guys I have a question

 graphs x^3 and x^3 + x, how would you know which is which? I know that the standard cubic is more steep, but once transformations are put in place, it can look very much like a standard cubic and I get confused all the time. 
If you had to find the equation of the graph, how would I know which graph it was? 
If the question gave us more co-ordinates, does it imply that it is of x^3+x form?
Lol idk if they will even give us a question like that..., but its just come about in my textbook.

thank you.

[Alwin]

Hey guys I have a question

 graphs x^3 and x^3 + x, how would you know which is which? I know that the standard cubic is more steep, but once transformations are put in place, it can look very much like a standard cubic and I get confused all the time. 
If you had to find the equation of the graph, how would I know which graph it was? 
If the question gave us more co-ordinates, does it imply that it is of x^3+x form?
Lol idk if they will even give us a question like that..., but its just come about in my textbook.

thank you.

Actually wouldn't the graph in form be more steeper?

Also, hint: look at the point of inflection. which form has a stationary point of inflection and which form doesn't.
hope it helps!

[Daenerys Targaryen]

If the where drawn together is the steeper one.
Remember it's just like a addition of ordinates question : Thus y-values become steeper

[shadows]

Thank you

Cleared up everything for me!

[Essendon2013]

Hey guys, need some help for a question.

The simultaneous linear equations
mx + 12y = 24
3x + my = m

Find the values for which m give
-> A unique solution
-> Infinitely many solutions

Help would be greatly appreciated!