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AEA Mathematics 25/06 2013 Thread Watch

  • View Poll Results: What do you think the Distinction grade boundary is likely to be?
    Greater than 85
    1
    2.78%
    82-85
    4
    11.11%
    78-81
    4
    11.11%
    74-77
    9
    25.00%
    70-73
    7
    19.44%
    66-69
    10
    27.78%
    65 or less
    1
    2.78%

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    (Original post by yl95)
    I got 7 solutions or something for theta...looks like it's a fail for me.
    Oh... I think this sounds right actually. I got one solution as being something like 3Th = 54+360n and the other as Th=70, and forgot to subtract from 180 degrees or whatever it should have been so I probably missed a few solutions.
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    (Original post by Math-Magician)
    The expansion would be valid, but (1+aX)^1 = 1+aX, and (1+aX)^0 = 1, so they both give no X^2 or X^3 terms and I'm sure the question said the coefficients of these were non-zero? The next part then asked you to reject one of the other two solutions (as they told you X=1/2 and this made mod(aX)>1)

    I definitely got 5/2 and -1/2 though so that's good!
    I'm pleased if you got four solutions for theta as I thought I'd included spurious solutions or something, it looked like there were too many

    I must have dropped 20-30 marks or so on this paper, plus all the style marks no doubt
    aaah I missed the non-zero part. I'm confused about trig solutions will need to double check, I think I may have had more than 4,was it x+17
    x+8?
    I'm hoping I didn't drop more than 30
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    (Original post by jarasta)
    aaah I missed the non-zero part. I'm confused about trig solutions will need to double check. was it x+17
    x+8?
    That rings a bell, but I have no idea about the actual answers, I just made up some numbers before to show what I did wrong!

    Plot the two graphs on the computer and see where they cross if you want to be sure.
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    I got 16 degrees for one of my theta values, I think...
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    (Original post by Math-Magician)
    Oh... I think this sounds right actually. I got one solution as being something like 3Th = 54+360n and the other as Th=70, and forgot to subtract from 180 degrees or whatever it should have been so I probably missed a few solutions.
    Yeah I had the initial solution, y+360n
    the (180-y)+360n
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    (Original post by yl95)
    I got 16 degrees for one of my theta values, I think...
    yeah I came out with 16.
    Ill show what I did
    2sin(x+17)=cos(x+8)/cos(x+17)
    2sin(x+17)cos(x+17)=sin(90-(x+8))
    sin(2x+34)=sin(82-x)
    so 2x+34=82-x... find 3x. then +360n divide by 3
    then 180-3x+360n, divide by 3
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    Oh, I did +180n...ugh.
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    (Original post by jarasta)
    yeah I came out with 16.
    Ill show what I did
    2sin(x+17)=cos(x+8)/cos(x+17)
    2sin(x+17)cos(x+17)=sin(90-(x+8))
    sin(2x+34)=sin(82-x)
    so 2x+34=82-x... find 3x. then +360n divide by 3
    then 180-3x+360n, divide by 3
    I just did it on an online graphing calculator and it looks like there should be 3 solutions

    Oops, I forgot to put it into radians, I'm getting Theta = 16, 64, 136, 256 using the first line of your post.

    Try it on here but remember to put it into radians first:
    https://www.desmos.com/calculator
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    Oh no! How much would I be penalised for extra solutions using +180n?
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    (Original post by Math-Magician)
    I just did it on an online graphing calculator and it looks like there should be 3 solutions

    Oops, I forgot to put it into radians, I'm getting Theta = 16, 64, 136, 256 using the first line of your post.

    Try it on here but remember to put it into radians first:
    https://www.desmos.com/calculator
    I got 4 from the graph, if i put the right things in and I remember getting those numbers
    Did anyone have a complete solution to the series one, not to double check what I did
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    My brain was utter mush, I don't think I managed to finish any of the final parts. No distinction for me.
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    (Original post by Appeal to reason)
    My brain was utter mush, I don't think I managed to finish any of the final parts. No distinction for me.
    Im thinking that the grade boundaries for a distinction might be closer to 70 than 80 this year given that a lot of people who would otherwise have scored well will have sat STEP first and then done worse in the AEA. :dontknow:
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    grade boundary poll?
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    (Original post by Math-Magician)
    Im thinking that the grade boundaries for a distinction might be closer to 70 than 80 this year given that a lot of people who would otherwise have scored well will have sat STEP first and then done worse in the AEA. :dontknow:
    I hope so, or that Warwick will take me with a merit given I get the A-levels grades I'm hoping for. A guy from last year got in with a Merit, so fingers crossed!
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    (Original post by jarasta)
    I hope so, or that Warwick will take me with a merit given I get the A-levels grades I'm hoping for.
    Didn't you take STEP I yesterday? I'm sure you'll have done enough to get into Warwick
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    When are we allowed to talk about STEP?
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    (Original post by Math-Magician)
    Im thinking that the grade boundaries for a distinction might be closer to 70 than 80 this year given that a lot of people who would otherwise have scored well will have sat STEP first and then done worse in the AEA. :dontknow:
    Its been close to 70 nearly every year?
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    (Original post by Math-Magician)
    When are we allowed to talk about STEP?
    I think its 1pm
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    (Original post by Appeal to reason)
    Its been close to 70 nearly every year?
    Oh really? Maybe it'll go even lower

    (Original post by MathsNerd1)
    I think its 1pm

    Ah, thanks. I'm going out so I have to wait until later. :cool:
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    (Original post by MathsNerd1)
    I think its 1pm
    Ah, thanks. I'm going out so I have to wait until later. :cool:
 
 
 
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