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Edexcel A2 C4 Mathematics June 2016 - Official Thread Watch

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    For my C4 on the last question, I drew a diagram showing the possible position vectors of P and then I also tried to solve to find lambda in the form of initially showing magnitude of PE = square root 8. But in subbing in my unit vector of PE (which was correct and I found), I forgot to put a square root around my magnitude for the vector so I couldn't find lambda as it was some weird decimal number which was recurring and so I couldn't solve for lambda and I didn't continue the question to find the possible position vectors. :/ How many marks do you think I lost cause that was the only question I lost marks in that whole paper.
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    Hey, I've been busy this weekend so the first time I've had a chance to think about c4. There was an implicit dy/dx question. I did the whole question in degrees and didn't realize -.- But I scribbled it out as well as I could but there was still some remnants of my working visible (through my scribbled lines) . I left a note underneath, "ignore this. I accidentally did this in degrees check next page for rad version" I re-did the question in rad and got it right

    But will i be penalized for this?
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    (Original post by countduckula1906)
    Hey, I've been busy this weekend so the first time I've had a chance to think about c4. There was an implicit dy/dx question. I did the whole question in degrees and didn't realize -.- But I scribbled it out as well as I could but there was still some remnants of my working visible (through my scribbled lines) . I left a note underneath, "ignore this. I accidentally did this in degrees check next page for rad version" I re-did the question in rad and got it right

    But will i be penalized for this?
    Nope that's perfectly fine

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    (Original post by Euclidean)
    Nope that's perfectly fine

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    That's awesome! thank you for the quick reply
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    Everyone else be getting quick replies and I'm just here like sigh.
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    (Original post by nonametosee)
    Everyone else be getting quick replies and I'm just here like sigh.
    I'd say you get one mark for forming the expression with lambda and one mark for subbing your positive and negative values of lambda to find OE. But if you only found one value for lambda then I'm not sure. I made a similar mistake where i got 2 wrong values for lambda, positive and negative but i still substituted 2 values into the same vector equation.
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    Oh no what I meant was I forgot to put a square root around my magnitude for my vector expression for PE which had lambda in it so I got some weird decimal number and so I didn't proceed any further with the question because I just had no confidence in my value for lambda. But what I did have was the diagram for showing 2 position vectors of PE and an expression for PE in terms of lambda and so I couldn't find my OE and an attempt to find magnitude of PE but just without the square root xD
    (Original post by RehanJak98)
    I'd say you get one mark for forming the expression with lambda and one mark for subbing your positive and negative values of lambda to find OE. But if you only found one value for lambda then I'm not sure. I made a similar mistake where i got 2 wrong values for lambda, positive and negative but i still substituted 2 values into the same vector equation.
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    Name:  13499886_1172148239483583_1118845100_o.jpg
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Size:  63.1 KB This was basically all I did (And I had some working left before but that was all wrong but I didn't cancel it out) Is it enough to lose only 2-3 marks?
    (Original post by RehanJak98)
    I'd say you get one mark for forming the expression with lambda and one mark for subbing your positive and negative values of lambda to find OE. But if you only found one value for lambda then I'm not sure. I made a similar mistake where i got 2 wrong values for lambda, positive and negative but i still substituted 2 values into the same vector equation.
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    usually its 1 mark for forming the correct quadratic expression, then 1 mark for the correct value for lambda, 1 method mark for substituting lambda to find both possible sets of co-ordinates and i'd say 2 accuracy marks for the 2 sets of co-ordinates. Judging by what you've done, I think you can get 1 mark max. with your diagram because it shows some understanding. If you substituted your vale of lambda in the vector equation (even though it was a weird value) you would have got a method mark.
    (Original post by nonametosee)
    Oh no what I meant was I forgot to put a square root around my magnitude for my vector expression for PE which had lambda in it so I got some weird decimal number and so I didn't proceed any further with the question because I just had no confidence in my value for lambda. But what I did have was the diagram for showing 2 position vectors of PE and an expression for PE in terms of lambda and so I couldn't find my OE and an attempt to find magnitude of PE but just without the square root xD
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    (Original post by RehanJak98)
    usually its 1 mark for forming the correct quadratic expression, then 1 mark for the correct value for lambda, 1 method mark for substituting lambda to find both possible sets of co-ordinates and i'd say 2 accuracy marks for the 2 sets of co-ordinates. Judging by what you've done, I think you can get 1 mark max. with your diagram because it shows some understanding. If you substituted your vale of lambda in the vector equation (even though it was a weird value) you would have got a method mark.
    Will the examiner not acknowledge that it may have been a slip in forgetting to put a square root around my magnitude of unit vector PE? If I am actually awarded 1 mark max. that's 71/75. Damn it, I've failed No 100 UMS since everyone is saying it was an easy paper.
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    (Original post by RehanJak98)
    usually its 1 mark for forming the correct quadratic expression, then 1 mark for the correct value for lambda, 1 method mark for substituting lambda to find both possible sets of co-ordinates and i'd say 2 accuracy marks for the 2 sets of co-ordinates. Judging by what you've done, I think you can get 1 mark max. with your diagram because it shows some understanding. If you substituted your vale of lambda in the vector equation (even though it was a weird value) you would have got a method mark.
    Oh god, would it be a mark for forming a quadratic? I used a method that didn't involve one, I found the magnitude of the direction vector of the line E and P were on, and equated the magnitudes - something like u5root2=2roo2 to determine that lambda had to be 2/5, and explained by concept it must be positive or negative. Would I get deducted marks for this? I didn't think a quadratic was necessary :/
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    I think I should get 100 UMS for both C3 and C4. The only thing that I'm worried about is in C3 when they asked for the minimum value of theta and I gave the correct answer but then also wrote the maximum value of theta as well. I labelled both of the values though. Hopefully I won't get penalised.
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    (Original post by somevirtualguy)
    Oh god, would it be a mark for forming a quadratic? I used a method that didn't involve one, I found the magnitude of the direction vector of the line E and P were on, and equated the magnitudes - something like u5root2=2roo2 to determine that lambda had to be 2/5, and explained by concept it must be positive or negative. Would I get deducted marks for this? I didn't think a quadratic was necessary :/
    Anyone?
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    (Original post by somevirtualguy)
    Anyone?
    I think there would be many ways to solve this question so you should get all the marks if you answered it correctly. (based on previous C4 markschemes)

    Hope that helps
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    Hi guys. Unfortunately exams didn't go too well for me this year. But I wanted to get your opinions of the chances of me getting an A.
    In core 3 I got around 55
    In core 4 I got around 61
    My stats 1 is around 64
    And I have 257 ums from last year. Any help is greatly appreciated.

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    (Original post by ImNervous)
    Hi guys. Unfortunately exams didn't go too well for me this year. But I wanted to get your opinions of the chances of me getting an A.
    In core 3 I got around 55
    In core 4 I got around 61
    My stats 1 is around 64
    And I have 257 ums from last year. Any help is greatly appreciated.

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    It's gonna be close but I reckon you might have just done it


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    (Original post by Supermanxxxxxx)
    It's gonna be close but I reckon you might have just done it


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    Thanks for your response. It's killing me just thinking about it. Haven't stopped since I came out of that C4 exam knowing I made stupid mistakes costing me marks. I guess I could retake next year. Ugh
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    (Original post by ImNervous)
    Thanks for your response. It's killing me just thinking about it. Haven't stopped since I came out of that C4 exam knowing I made stupid mistakes costing me marks. I guess I could retake next year. Ugh
    Should be OK. You're looking at mid-B's for C3 and C4 (although the C4 mark will be a high B) but S1 is likely to be between 85-90 UMS (its definitely gonna be sub 60 for an A on that, most likely 57/58) and that combined with 257 UMS for your AS year will put you over the A.
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    (Original post by Fas)
    Should be OK. You're looking at mid-B's for C3 and C4 (although the C4 mark will be a high B) but S1 is likely to be between 85-90 UMS (its definitely gonna be sub 60 for an A on that, most likely 57/58) and that combined with 257 UMS for your AS year will put you over the A.
    Thank you aswell. Giving me hope.
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    What UMS do you guys think 71 or 72 out of 75 is gonna get me in C4? I really wanted 100 UMS but I guess not anymore since I messed up C4.
 
 
 
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