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    (Original post by bartbarrow)
    Say you have du/dx and you need to find the maximum or minimum rate of growth:

    Imagine setting y=du/dx and plotting y

    The maximum/minimum rate of growths are going to be stationary points so you can differentiate y (or in other words, differentiate du/dx) and equate to 0 to find stationary points. Where d^2u/dx^2 = 0 will give you those points, then you can differentiate it again (d^3u/dx^3) and plug those values in, if it is < 0 you have found the maximum and if it is > 0 you have found the minimum.
    oh, okay! that makes so much more sense. thank you!
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    Good luck everyone
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    Hardest vector question? Wanna give it a go now before exam!
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    this papers gonna fk us all over, i said it first init
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    Good luck everyone, hopefully AQA are nice to us after c3.
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    90 minutes today may change the course of my whole life
    because my course does not allow resits :[
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    Grade boundary is gonna be 25 for an A*
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    It will be a normal exam, just the standard questions.
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    (Original post by MahuduElec)
    It will be a normal exam, just the standard questions.
    I think it will be, too


    Posted from TSR Mobile
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    chem4 and c3 were terrible but bio4 was really nice so i cant even predict the difficulty, i will have to work hard for d2 so i can pull the grades up
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    :bricks::bricks:
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    Found it a rather generous paper, ( relative to the PC3, am I right?), very happy. - William Moore signing off.
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    (Original post by WilliamMoore)
    Found it a rather generous paper, ( relative to the PC3, am I right?), very happy. - William Moore signing off.
    I concur fellow student, very happy, glad we got that partial fractions integration question! Can't believe I managed to come to a coherent answer for the last question. O M G !
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    Surprisingly nice paper. The very last question was something from FP2 syllabus though... Not too fair on non FM people.
    (although it could be easily done with C4 skill)
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    Anyone tell me their method for vectors and their answer?
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    Anyone else get 330 days for the half life question?

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    I ran out of time but I thought it was okay.
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    (Original post by RedNebula)
    Anyone else get 330 days for the half life question?

    Posted from TSR Mobile
    wasn't it 331 because it was 330 point something so it had to round up?
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    (Original post by 000536)
    wasn't it 331 because it was 330 point something so it had to round up?
    It's 330 because I got 330.01... and it was to the nearest day.
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    (Original post by acenog123)
    It's 330 because I got 330.01... and it was to the nearest day.
    No it is 331 days because at exactly 330 days, the half life hasn't yet been achieved so you have to do it to the next day :-)
 
 
 
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