ATAR Notes: Forum
VCE Stuff => VCE Mathematics => VCE Mathematics/Science/Technology => VCE Subjects + Help => VCE Mathematical Methods CAS => Topic started by: costargh on November 04, 2007, 02:53:48 pm
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I just did last years VCAA methods cas exam 1 2006 ( same as the methods exam one for 2006 and got 14/40!
Yeh pathetic.
Main problematic areas are
-anything to do with logs and differentiating them or 'e' functions or whatever
-questions like
f(x)= x/12 1<x<5 (signs should be greater than or equal to)
0 otherwise
Find pr( x <3)
- trouble understanding |f(x)| stuff
- anything with complicated notation
my area of strength is probability but even by hand i kinda suck @ it.
what should i do! lol
try do better on areas of weakness or focus on strengths?
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I just did last years VCAA methods cas exam 1 2006 ( same as the methods exam one for 2006 and got 14/40!
Yeh pathetic.
Main problematic areas are
-anything to do with logs and differentiating them or 'e' functions or whatever
-questions like
f(x)= x/12 1<x<5 (signs should be greater than or equal to)
0 otherwise
Find pr( x <3)
- trouble understanding |f(x)| stuff
- anything with complicated notation
my area of strength is probability but even by hand i kinda suck @ it.
what should i do! lol
try do better on areas of weakness or focus on strengths?
Well... the formula sheet has the differentiation rules for logs and e^x functions.
The hybrid function ones are usually pretty simple, they are always about anti-differentiation and the 1<x<5 bit gives you your terminals generally.
|f(x)| is the modulus of f(x), hence anything below the y-axis becomes positive.
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You only need 8/40 to get a 25. You should be fine. Concentrate on honing your probability skills, and try to understand other concepts to give a half-assed answer (try to grab half-marks and stuff). But don't bullshit too much, or the examiner will get sick of it, and give 0 for anything that's half-incorrect.
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You only need 8/40 to get a 25..
really?? how do you know this? what about 30?
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You only need 8/40 to get a 25..
really?? how do you know this? what about 30?
yeh im wondering how you know that to lol
did you use the mean and std dev to work it out or sometin? lol
cause iv been tryin 2 work it out 4 ages
how about for exam 2 what sorta mark do i need (if u know) cause im about 2 go do that now
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ohh and if possible (if your working it out using the data that vcaa provides)... can you work it out according to methods cas? if not they should be pretty similar marking distribution yeh?
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Nah I heard it from some dumbcunts who were talking about getting 25 in Methods, and they asked their Methods coordinator about 2006 results.
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I'm one of those dumbcunts :oops:
=p
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man i'll be glad if i get 25, maths is by farr my shittest subject...i used to love it but then along came some teacher who knows the stuff but can't teach it really well.
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man i'll be glad if i get 25, maths is by farr my shittest subject...i used to love it but then along came some teacher who knows the stuff but can't teach it really well.
lol umm... you sound exactly the same as me. =(
I just did last years vcaa exam 2
got 33/80
would give me a C according to last years grade distributions which would probably JUST get me a 25. I want it so bad *cries* lol
I might get someone to go thru the exam with me and show me where I should have got more marks and stuff
So many stupid mistakes grr.
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man i'll be glad if i get 25, maths is by farr my shittest subject...i used to love it but then along came some teacher who knows the stuff but can't teach it really well.
lol umm... you sound exactly the same as me. =(
I just did last years vcaa exam 2
got 33/80
would give me a C according to last years grade distributions which would probably JUST get me a 25. I want it so bad *cries* lol
I might get someone to go thru the exam with me and show me where I should have got more marks and stuff
So many stupid mistakes grr.
I can do that in person after the 7th if you want. I'll still charge of course.
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are you getting questions wrong, or just not even knowing how to approach them?
if its the second one, just do some exams with your notes and text book, or even with the answers, and then work through and make sure you understand them. look at the answers for how you'd do it, then write it all out, steps etc, and hopefully when a similiar question pops up you'll know what to do
if you're getting questions wrong, is it because of silly arithmatic mistakes, or are you doing the question in a completely disastrous way? if its artithmatic, make sureyou always check your working really thoroughly. its its the latter.. you probably need to go through it with a teacher or get a session with a tutor who can explain and you can work out where you're going wrong
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are you getting questions wrong, or just not even knowing how to approach them?
if its the second one, just do some exams with your notes and text book, or even with the answers, and then work through and make sure you understand them. look at the answers for how you'd do it, then write it all out, steps etc, and hopefully when a similiar question pops up you'll know what to do
if you're getting questions wrong, is it because of silly arithmatic mistakes, or are you doing the question in a completely disastrous way? if its artithmatic, make sureyou always check your working really thoroughly. its its the latter.. you probably need to go through it with a teacher or get a session with a tutor who can explain and you can work out where you're going wrong
Thanks for the advice :)
I guess it's a combination of both. I've realised I know more than I thought I knew so I guess that I've been able to do some questions because I remember how to do them. Other ones I have been able to learn over the last two days... the concepts just seem easier to understand now. Still not getting the best marks but some of them I have no idea how to approach them so I'm going to take them in to my methods teacher on Wednesday and organise for her to go through the ones I have no idea how to do.
Some of them are pretty basic concepts I dont understand ( I can see this by the fact that on the assessment reports , sometimes 80% or above of students have achieved the correct response). So hopefully I should be able to learn a bit more before the exam.
Thanks for the help melanie.dee.
I just did another practice exam (VCAA 2005 Exam 1 (for CAS))
I got 20/50 whick once again puts me into the 'C' marking range according to the exams grade distribution. So far that is 3 'C' ranges from 3 attempted exams.
Thoughts on whether that will be enough for a 25 SS? :?
Coblin has already said he thinks it will be. I hope it will be enough =S
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vcaa tells me that 78% of students get 25 or over. therefore to get 25 you have to beat 22%.
the grade distribution for methods cas last year tells me that a C was equivalent to the top 77%.. therefore moral of story. a C should get you 25. however this is not taking into account sacs. but lets assume they scale to be around the same or better than your exam mark.
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Yeh thanks. I just went and did my own research on VCAA website and found same thing. Also take into account that my C's have been mid range C's (from memory) and not border line C's and I guess that from now until friday and monday I can only really go up... I just emailed my teacher. Hope she writes back over the long weekend lol...although I doubt it.
At least if I can get my C's up to a high C range or maybe even a C+ I will feel a lot more confident that I can get my 25!
Thanks heaps to everyone that has helped and advised me and stuff!
One question...
The function f: [a,∞) --> R with rule f(x) = 2(x-3)^2 + 1 will have an inverse function if
A. a ≤ -3
B. a ≥ -3
C. a ≥ 1
D. a ≤ 3
E. a ≥ 3
??? explanation?
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Yeh thanks. I just went and did my own research on VCAA website and found same thing. Also take into account that my C's have been mid range C's (from memory) and not border line C's and I guess that from now until friday and monday I can only really go up... I just emailed my teacher. Hope she writes back over the long weekend lol...although I doubt it.
At least if I can get my C's up to a high C range or maybe even a C+ I will feel a lot more confident that I can get my 25!
Thanks heaps to everyone that has helped and advised me and stuff!
One question...
The function f: [a,∞) --> R with rule f(x) = 2(x-3)^2 + 1 will have an inverse function if
A. a ≤ -3
B. a ≥ -3
C. a ≥ 1
D. a ≤ 3
E. a ≥ 3
??? explanation?
well taking into account im shit at methods and am aiming for 25 too haha.. therefore might be wrong
to have an inverse function, it must be 1:1 ie each x value corresponds to a single y value, and vice versa
seeing as that is a parabola
it can only have an inverse for like one half of it (if that makes sense haha. like split it through the minimum)
the equation tells you its been shifted 3 to the right (x-3) or you could even graph it if you need. there the x coordinate of the minimum or midway point is 3
they've defined the upper domain as inifinite.. therefore you need the right hand side of the parabola.. which starts at 3
therefore the answer is a > or equal to 3
therefore answer is E
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is that right? according to the answers? i could be wrong haha
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Yep thats right
74% of people got that right. I still dont get why its only one half of the parabola (as you said)
=S
argh I feel dumb
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yeh but remember methods is a scewed population, you get people above the average sort of vce intelligence doing it, because those that arnt do further or no maths. so thats 74% of an already smart population.. so dont worry about it
anyway um do you get what i mean by 1:1? because for a parabola, a y value is going to correspond to two x values.. ie if you draw a horizontal line accross the graph, its going to hit the graph in 2 points.
for a graph to have an inverse, it CANT do that. it can only hit it in one point. therefore, for an inverse you need to work out what part of the graph gives you only a value of x for each y value. for a parabola, you simply cut it down the middle. both halves can have an inverse.
like for that one above you could have an inverse from neg infinity to 3, and then from 3 to positive infinity. yeh? except in the question they've already defined the upper boundary as positiv infinity.. therefore you know its the '3 to pos infinity' half of the of the graph.
do you get it kinda? im not sure how else to explain it. find the section on inverses in your text book
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yeh i know what one to one function is and then OMG i just realised lol shitt i get it now lol... ok so if its a parabola just look at one half of the graph because their symmetrical and if you have both parts of the graph on the left and right of the turning point then when u draw a horizontal line it will cross twice meaning its not one to one.
OMG I BLOODY UNDERSTAND NOW!!! thank youuuuuuu omg seriously thank you. Quoted by Celine Dion " its all coming back to me"
heheh
thanks !
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In my opinion costargh, you should have done accounting in year 11, instead of methods. Since you may have the capability to do better in year 12. I wish i did that.
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Ive been doing a year ahead in maths since year 7 do it bas just a formality to do methods 3/4 in year 12. Didnt have the choice ( well i did...)