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AQA A2 Mathematics MPC4 Core 4 - 9th June 2015 [Discussion & unofficial markscheme] Watch

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    (Original post by student0042)
    I'm starting to prepare now, but will do more over the summer.




    I just said max when N = 250, which in the mark scheme gives 2 marks instead of differentiating it. I understand it better that way.
    That makes sense.


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    Hey, how's prep going for that A*!!!!?

    I was gonna ask a question...
    I don't know if you've done the june 2014 c3 paper but i really got caught out by that inverse question for the quadratic.. im still bamboozled by what the thought process is to do it... I just know there is gonna be something like that again in the exam this year
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    (Original post by madmenace)
    Hey, how's prep going for that A*!!!!?

    I was gonna ask a question...
    I don't know if you've done the june 2014 c3 paper but i really got caught out by that inverse question for the quadratic.. im still bamboozled by what the thought process is to do it... I just know there is gonna be something like that again in the exam this year
    http://www.thestudentroom.co.uk/show...3#post56093833

    Hopefully this clears it up.


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    stuck on question 1

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    (Original post by tomixox)
    how did you calculate that max is 250 without differentiating it?
    By inspection, I guess you could also try different values and find that 250 is a max...
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    (Original post by the_googly)
    stuck on question 1

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    problem solved

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    (Original post by the_googly)
    stuck on question 1

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    How did you do B?


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    (Original post by CD223)
    How did you do B?


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    correct?


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    stuck on question 3b now..

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    (Original post by the_googly)
    correct?


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    I'm just puzzled why you set it to equal zero. Surely that just implies the lines are perpendicular?


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    (Original post by the_googly)
    stuck on question 3b now..

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    Don't you just integrate the partial fractions you have found in part a with respect to x and then integrate 1/4y with respect to y and them rearrange to get y=f(x)


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    (Original post by the_googly)
    stuck on question 3b now.
    (Original post by Jimmy20002012)
    Don't you just integrate the partial fractions you have found in part a with respect to x and then integrate 1/4y with respect to y and them rearrange to get y=f(x)
    Don't know about you both but I got this:

    Name:  ImageUploadedByStudent Room1432493236.956934.jpg
Views: 106
Size:  153.4 KB

    If you sub in y=2, x=1 you get k=18.

    If you then sub x=10 into my final equation, that gives y=12.5 when x=10.

    Is this correct?

    Technically the constant should also be raised with e, making it the multiplier that I've renamed k.
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    (Original post by CD223)
    I'm just puzzled why you set it to equal zero. Surely that just implies the lines are perpendicular?


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    the closest point would be the point perpendicular?

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    (Original post by Jimmy20002012)
    Don't you just integrate the partial fractions you have found in part a with respect to x and then integrate 1/4y with respect to y and them rearrange to get y=f(x)


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    I did that but couldn't get the correct answer

    the book says y=Ax^2/(x+2)^2

    is this correct?

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    (Original post by the_googly)
    the closest point would be the point perpendicular?

    I see.

    Have a look at my above workings. They show the book to be correct. Their A is my k.

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    (Original post by CD223)
    I see.

    Have a look at my above workings. They show the book to be correct. Their A is my k.

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    thanks a lot!.

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    (Original post by CD223)
    Don't know about you both but I got this:

    Name:  ImageUploadedByStudent Room1432493236.956934.jpg
Views: 106
Size:  153.4 KB

    If you sub in y=2, x=1 you get k=18.

    If you then sub x=10 into my final equation, that gives y=12.5 when x=10.

    Is this correct?

    Technically the constant should also be raised with e, making it the multiplier that I've renamed k.
    yep y = 12.5

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    (Original post by the_googly)
    yep y = 12.5

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    Cool! Glad it's correct. Do my workings make sense?


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    Ballin for this exam now, think it's gonna be a right ******* of a paper

    The only annoying part is that I could not even sit it and get an A, but I need that 90 for an A*, weird system
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    (Original post by Stepidermis)
    Ballin for this exam now, think it's gonna be a right ******* of a paper

    The only annoying part is that I could not even sit it and get an A, but I need that 90 for an A*, weird system
    How does that work out? What UMS are you on?


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