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VCE Stuff => VCE Mathematics => VCE Mathematics/Science/Technology => VCE Subjects + Help => VCE General & Further Mathematics => Topic started by: physics on November 02, 2010, 10:59:50 am

Title: FURTHER TRAIL QUESTIONSSSSSSSSSS help!!!!!!!!!!! =D
Post by: physics on November 02, 2010, 10:59:50 am: When they ask you to write down the conefficient of determination do you write it in eg.0.987 or 98.7%

cause i dunno if vcaa will deduct a mark for writing it down as a decimal rather then percentage..

thank you for the help
Title: Re: coefficient of determination help!!!!!!!!!!! =D
Post by: _avO on November 02, 2010, 11:00:48 am: Percentage when interpreting the variables, but decimal if just calculating. Or am I wrong?

Actually I think percentage for all cases, but be mindful of decimal places they will specify it
Title: Re: coefficient of determination help!!!!!!!!!!! =D
Post by: physics on November 02, 2010, 11:10:56 am: oh wait i reread the question and it said percentage =D thanks!
Title: Re: FURTHER TRAIL QUESTIONSSSSSSSSSS help!!!!!!!!!!! =D
Post by: physics on November 02, 2010, 11:14:24 am: i have another question..
a question says that i must sell atleast as many x as i do of y
which would give x>= y

but then answer says x-y>=0
is my answer wrong then????????
Title: Re: FURTHER TRAIL QUESTIONSSSSSSSSSS help!!!!!!!!!!! =D
Post by: brightsky on November 02, 2010, 11:15:59 am: They're the same.

$x \geq y$

Take y from both sides:

$x - y \geq 0$
Title: Re: FURTHER TRAIL QUESTIONSSSSSSSSSS help!!!!!!!!!!! =D
Post by: physics on November 02, 2010, 11:18:01 am: I was wondering about the feasible regions...if it was something that requires whole numbers and the max vertice is a decimal can we round off the answer and use that aanswer even if it is outside the feasible region?
Title: Re: FURTHER TRAIL QUESTIONSSSSSSSSSS help!!!!!!!!!!! =D
Post by: _avO on November 02, 2010, 11:20:42 am: No, like last year they moved an integer (or more) across so that it is still in the feasible region, and is the 2nd highest profit (or lowest cost) and therefore it is still logical
Title: Re: FURTHER TRAIL QUESTIONSSSSSSSSSS help!!!!!!!!!!! =D
Post by: _avO on November 02, 2010, 11:21:17 am: In saying this I don't think they will do it this year as it has probably been taught in class so therefore everyone is aware, they want trick questions!
Title: Re: FURTHER TRAIL QUESTIONSSSSSSSSSS help!!!!!!!!!!! =D
Post by: physics on November 02, 2010, 11:25:59 am: Quote from: _avO on November 02, 2010, 11:20:42 am
No, like last year they moved an integer (or more) across so that it is still in the feasible region, and is the 2nd highest profit (or lowest cost) and therefore it is still logical
sorry. i dont get it. so it has to be inside the feasible region even if it isnt the max profit or something?
Title: Re: FURTHER TRAIL QUESTIONSSSSSSSSSS help!!!!!!!!!!! =D
Post by: _avO on November 02, 2010, 11:30:13 am: Yep if its outside the feasible region, it doesnt satisfy all constraints and therefore defeats the purpose of the question. What you do is just count left or right from the point (which would be the maximum) that still fits inside the feasible region and find the 2nd highest profit.

Refer to 2009 exam last question in graphs http://www.vcaa.vic.edu.au/vcaa/vce/studies/mathematics/further/pastexams/2009/2009furmath2-w.pdf. The maximum profit point was (4.5,5.5) but they were talking about a number of flights. The solutions provided (http://www.vcaa.vic.edu.au/vcaa/vce/studies/mathematics/further/assessreports/2009/further2_assessrep_09.pdf) suggests that (2,7) is the optimum point as it is the 2nd highest profit in the feasible region and is logical (you can't have 4.5 flights :P)
Title: Re: FURTHER TRAIL QUESTIONSSSSSSSSSS help!!!!!!!!!!! =D
Post by: physics on November 02, 2010, 11:40:18 am: Quote from: _avO on November 02, 2010, 11:30:13 am
Yep if its outside the feasible region, it doesnt satisfy all constraints and therefore defeats the purpose of the question. What you do is just count left or right from the point (which would be the maximum) that still fits inside the feasible region and find the 2nd highest profit.

Refer to 2009 exam last question in graphs http://www.vcaa.vic.edu.au/vcaa/vce/studies/mathematics/further/pastexams/2009/2009furmath2-w.pdf. The maximum profit point was (4.5,5.5) but they were talking about a number of flights. The solutions provided (http://www.vcaa.vic.edu.au/vcaa/vce/studies/mathematics/further/assessreports/2009/further2_assessrep_09.pdf) suggests that (2,7) is the optimum point as it is the 2nd highest profit in the feasible region and is logical (you can't have 4.5 flights :P)
thank you =D i'm doing vcaa 2007 atm :(