Official 2005 CSSA Trial Exam Thread (1 Viewer)

ar3nbe

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c_james said:
Yeah, I understand what you mean, but you could've done the question without even having to find the second derivative by using the first derivative test - that is, you could've just tested points on either side. Much less messy and time consuming for that particular question.
I was thinking of doin that, but then i thought to realy "prove" it that way, you would have to test a whole lot of points. Its one of those questions that common sense can tell you the answer straight away, but we gotta show it. But really, i dont think they would take marks of you. Well done
 

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c_james said:
Yeah, I understand what you mean, but you could've done the question without even having to find the second derivative by using the first derivative test - that is, you could've just tested points on either side. Much less messy and time consuming for that particular question.
yeah true but i had about half an hour to go at that stage so time didnt really matter...
 

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ok i started a CSSA 3u forum in the 3u section.. feel free to post there
 

ar3nbe

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alex_london0 said:
although with the marking dont they look at how u got their and if you got the answer???? like they cant disputer whether or not you did it mathematically correct can they???
No they cant, BUT, they can argue that you didnt do what the question asked. If they said prove, then testing a point either side really isnt proving, its showing. Key verbs are in maths aswell. As for qu10 today, i cant remember what the actual wording of the question was, but i had some spare time, so i thought i better b safe dan sorry. Plus theres alwayz the feeling of being able to get question 10, and being able to to something you thought would b tricky :)
 

c_james

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alex_london0 said:
although with the marking dont they look at how u got their and if you got the answer???? like they cant disputer whether or not you did it mathematically correct can they???
If the question says "find", "solve" or "calculate" you are not required to show any working. If it's worth 3 marks and you give the correct answer without working, you get the 3 marks.

If, however, it says "show" or "prove" or something to that effect, you're required to show mathematically correct working. If you simply write down the answer without crucial steps you'll likely get 1 out of 3 marks.
 

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My teacher told me that showing the concavity changes on both sides by that first derivative rule is fine. Im pretty sure the question didnt say 'prove'
 

c_james

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ar3nbe said:
No they cant, BUT, they can argue that you didnt do what the question asked. If they said prove, then testing a point either side really isnt proving, its showing. Key verbs are in maths aswell. As for qu10 today, i cant remember what the actual wording of the question was, but i had some spare time, so i thought i better b safe dan sorry. Plus theres alwayz the feeling of being able to get question 10, and being able to to something you thought would b tricky :)
In this case it comes down to semantics. I would say testing a point on either side is proving. You don't need a written proof per se to prove something.
 

!lukey!

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the question was show that the value of D in the equation in part (i) is a minimum when y=2...
 

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c_james said:
If the question says "find", "solve" or "calculate" you are not required to show any working. If it's worth 3 marks and you give the correct answer without working, you get the 3 marks.

If, however, it says "show" or "prove" or something to that effect, you're required to show mathematically correct working. If you simply write down the answer without crucial steps you'll likely get 1 out of 3 marks.
yeh i know but it doesnt mean you must use formulas that you have been taught to find the answer does it??? like if where told something by someone and that worked could you use that to the same effect as using something you where taught in clas??
 

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!lukey! said:
the question was show that the value of D in the equation in part (i) is a minimum when y=2...
Then your fine! Hay u know the absolute values ques at the very start, were there 4 possible answers?
 

ar3nbe

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alex_london0 said:
yeh i know but it doesnt mean you must use formulas that you have been taught to find the answer does it??? like if where told something by someone and that worked could you use that to the same effect as using something you where taught in clas??
Think about this, if the question is worth 3marks, then there prob looking at more than just an answer. But it all depends on the question, and what uve learned, bla bla bla. Most of it comes from the proof anyway. Its notmally the same stuff
 

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evette13 said:
Then your fine! Hay u know the absolute values ques at the very start, were there 4 possible answers?
there were 4 yes, but 1 correct.... -6 lol
 

ar3nbe

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goan_crazy said:
How did you do 10a?
I wasnt 100% sure on that on, i did all i knew to do. If you could tell me the question tho, coz i cant remember it. PM it if were not allowd to mention it in the forum
 

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