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Edexcel A2 D2 Mathematics June 2016 - Official Thread Watch

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    Edexcel D2 - 29th June 2016

    Due to a number of posts on the 2015 exams thread, I think it's time to make a new thread for questions related to the 2016 D2 exam this year.

    Tagged: Zacken economicss


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    How do you define the state, action, destination and value for dynamic programming? I went over it briefly in class, but I don't get how you decide which ones which.
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    (Original post by Euclidean)
    Edexcel D2 - 29th June 2016

    Due to a number of posts on the 2015 exams thread, I think it's time to make a new thread for questions related to the 2016 D2 exam this year.
    Thanks for making this thread OP! I've added it to the Exam Directory Thread which you can find here. Use that thread to find discussions on your other exam papers, and do let me know if you spot any that aren't on the list. Good luck with this exam!
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    Hi, please could anyone explain how to do the dynamic programming for question 8 on this paper? https://3cb8366df74746bcd8eec8f4a703...%20Edexcel.pdf I really can't get my head around it, why is it we start with fresh rather than canned? Thanks
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    (Original post by economicss)
    Hi, please could anyone explain how to do the dynamic programming for question 8 on this paper? https://3cb8366df74746bcd8eec8f4a703...%20Edexcel.pdf I really can't get my head around it, why is it we start with fresh rather than canned? Thanks
    Euclidean Could you help please?
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    (Original post by economicss)
    Hi, please could anyone explain how to do the dynamic programming for question 8 on this paper? https://3cb8366df74746bcd8eec8f4a703...%20Edexcel.pdf I really can't get my head around it, why is it we start with fresh rather than canned? Thanks
    The stage order isn't so important as the algorithm can be performed in any order (imagine if you swapped the Fresh row for the Canned row in the table, the result and solution would be the same).

    If you look to the second page of the answer to that question, there is only a deduction of marks for an empty or an error in a stage cell. An error in this case I assume is a spelling error.

    They have done it from top (fresh) to bottom (canned) probably because that's the way the information is presented. But the order in which it is done won't matter to the solution and hence the marks if the method is correct.
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    (Original post by Euclidean)
    The stage order isn't so important as the algorithm can be performed in any order (imagine if you swapped the Fresh row for the Canned row in the table, the result and solution would be the same).

    If you look to the second page of the answer to that question, there is only a deduction of marks for an empty or an error in a stage cell. An error in this case I assume is a spelling error.

    They have done it from top (fresh) to bottom (canned) probably because that's the way the information is presented. But the order in which it is done won't matter to the solution and hence the marks if the method is correct.
    Thank you, please could you explain the table for frozen, I always get stuck with the middle part of the table, and is it the case in all of these types of questions that in the first stage that the destination will be 0 for every state? Thanks
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    Please could anyone explain exercise C question 4d https://1cb7ab25ef4ef909bacd98c7d41a...DZuaGc/CH4.pdf Haven't seen a question like this in the past papers, thanks
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    (Original post by economicss)
    Please could anyone explain exercise C question 4d https://1cb7ab25ef4ef909bacd98c7d41a...DZuaGc/CH4.pdf Haven't seen a question like this in the past papers, thanks
    Anyone got any ideas please?
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    (Original post by economicss)
    Anyone got any ideas please?
    It's unlikely that we'll be examined on that type of question, it has always been on just using the algorithm thus far.

    That being said, in the previous part of the question, you first start by "increasing" the Y coordinate which would be the same as moving up the y axis until you reach the vertex bounding the feasible region (which is the point A in the question).
    If you were to increase X then you would move along the X axis until you reach point D.
    The final point would be point C where the two lines intersect, which gives the maximum profit, and what was worked out earlier on in the question.
    Reading the pages on how the simplex tableu works on earlier pages in that book or watching videos on the algebraic simplex method may help make sense of it if what I said didnt come about clear enough
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    (Original post by JackSpinner1)
    It's unlikely that we'll be examined on that type of question, it has always been on just using the algorithm thus far.

    That being said, in the previous part of the question, you first start by "increasing" the Y coordinate which would be the same as moving up the y axis until you reach the vertex bounding the feasible region (which is the point A in the question).
    If you were to increase X then you would move along the X axis until you reach point D.
    The final point would be point C where the two lines intersect, which gives the maximum profit, and what was worked out earlier on in the question.
    Reading the pages on how the simplex tableu works on earlier pages in that book or watching videos on the algebraic simplex method may help make sense of it if what I said didnt come about clear enough
    Thanks so much sorry for the slow reply!
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    Could anyone explain exercise C question 2b please https://1cb7ab25ef4ef909bacd98c7d41a...DZuaGc/CH7.pdf I don't understand why none of the states ever have actions of 15, 20 or 25 because they're in the table? Thanks
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    Hey all - got to learn D1 in a week then can purely focus on D2. I am about halfway through - not very confident at some stuff but have a grasp, I like the Hungarian algorithm and northwest coroner method, and once D1 is done, I'm going to really entrench time into D2. Would you say you could become quite good at it with 1-2 weeks of solid revision on it? Bit worried I have left it to late.
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    (Original post by TrueDAN)
    Hey all - got to learn D1 in a week then can purely focus on D2. I am about halfway through - not very confident at some stuff but have a grasp, I like the Hungarian algorithm and northwest coroner method, and once D1 is done, I'm going to really entrench time into D2. Would you say you could become quite good at it with 1-2 weeks of solid revision on it? Bit worried I have left it to late.
    I started D2 about 5 days before the exam and got 98

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    (Original post by economicss)
    Could anyone explain exercise C question 2b please https://1cb7ab25ef4ef909bacd98c7d41a...DZuaGc/CH7.pdf I don't understand why none of the states ever have actions of 15, 20 or 25 because they're in the table? Thanks
    Euclidean Could you help please?
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    (Original post by economicss)
    Euclidean Could you help please?
    The first sentence in the question says that the project needs to be completed in 30 days.

    If we use 15 days in one, at minimum we have 15+5+5+5=30 days which is just on the allowed time for the project.

    Hence we can only use actions less than 15.

    You could do it including 15 as an action but you'd see it would never be used.
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    (Original post by Euclidean)
    I started D2 about 5 days before the exam and got 98

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    That's insane well done ! Hopefully i can grab a mark like that - would be super nice! Any tips? I've watched FMSP videos on it and compiled notes on 7/8 the topics. Is the key to it just past papers and some memory each now and then? And the same applies for D1?
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    (Original post by TrueDAN)
    That's insane well done ! Hopefully i can grab a mark like that - would be super nice! Any tips? I've watched FMSP videos on it and compiled notes on 7/8 the topics. Is the key to it just past papers and some memory each now and then? And the same applies for D1?
    Papers I think are the key, a little bit of understanding for the DP and Tableaux stuff is helpful.

    I don't remember making any notes except jottings in the textbook when I thought something was worth noting.

    I'd say do papers and study mark schemes, unfortunately with decision (and most other modules imo) you just gotta learn to play Edexcel's game.

    Best of luck!
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    (Original post by Euclidean)
    The first sentence in the question says that the project needs to be completed in 30 days.

    If we use 15 days in one, at minimum we have 15+5+5+5=30 days which is just on the allowed time for the project.

    Hence we can only use actions less than 15.

    You could do it including 15 as an action but you'd see it would never be used.
    Thank you!
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    D1 was awful - expecting high 60s and will probably have high 40s DAMNNNN! Gonna get the grind going for D2 now, hopefully it goes much better
 
 
 
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