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Edexcel FP3 - 27th June, 2016 watch

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    (Original post by blahblah21)
    please explain again please, if you dont mind, sorry to bother
    There you go. I hope that explains it. If not just tell me and I'll be glad to explain further.
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    (Original post by target21859)
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    There you go. I hope that explains it. If not just tell me and I'll be glad to explain further.
    Yeah I get it now thank you (:
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    (Original post by blahblah21)
    Yeah I get it now thank you (:
    No problem
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    Learning Fp3 atm

    Can someone help me with a reduction formulae question from the book?

    You're given \displaystyle I_n=\int_0^a(a^2-x^2)^n \text{d}x.

    I tried IBP setting u=(a^2-x^2)^n but ended up having to deal with an \displaystyle \int_0^ax^2(a^2-x^2)^n \text{d}x integral and the power of x increases by 2 each time you try to IBP it so clearly that's a dead end.
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    (Original post by target21859)
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    There you go. I hope that explains it. If not just tell me and I'll be glad to explain further.
    Sir i still didnt get why we put a 2π in the formula instead of one... in my mind a i see that with a single pi a full circle is formed 🤔?
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    (Original post by Kvothe the arcane)
    Learning Fp3 atm

    Can someone help me with a reduction formulae question from the book?

    You're given \displaystyle I_n=\int_0^a(a^2-x^2)^n \text{d}x.

    I tried IBP setting u=(a^2-x^2)^n but ended up having to deal with an \displaystyle \int_0^ax^2(a^2-x^2)^n \text{d}x integral and the power of x increases by 2 each time you try to IBP it so clearly that's a dead end.
    does it not tell you to show something? Sure one could find a formula without having something to aim for but I don't recall many questions not having that..
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    May the force be with you all
    I have 2 days to prepare for FP3 and S2................
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    (Original post by 13 1 20 8 42)
    does it not tell you to show something? Sure one could find a formula without having something to aim for but I don't recall many questions not having that..
    It does.

    Given that \displaystyle I_n=\displaystyle \int_0^a (a^2-x^2)^n \text{d}x where a is a positive constant,

    show that, for n>0, I_n=\dfrac{2na^2}{2n+1}I_{n-1}.
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    (Original post by lawlieto)
    May the force be with you all
    I have 2 days to prepare for FP3 and S2................
    Same. I'm actually learning a lot of it in those 2 days too :/.
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    (Original post by Kvothe the arcane)
    Same. I'm actually learning a lot of it in those 2 days too :/.
    I did S2 and FP3 in May last time... I kind of forgot a lot, I had 9 exams in the meantime, I was concentrating on those...
    S2 is kind of ok i think, 1 day is probably enough but FP3 is a different thing
    how important is S2/FP3 for meeting your offer?
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    I'm rekt for my Physics A level as well as this module. :lol:
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    (Original post by lawlieto)
    I did S2 and FP3 in May last time... I kind of forgot a lot, I had 9 exams in the meantime, I was concentrating on those...
    S2 is kind of ok i think, 1 day is probably enough but FP3 is a different thing
    how important is S2/FP3 for meeting your offer?
    I don't know. 50% of me thinks I have met the A* requirement in Chemistry in which case I only need to get a C in S2 or A in Fp3 (UC originally) to get an A overall.
    But if I need an A* then one of them will have to be over 90%.
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    (Original post by Kvothe the arcane)
    It does.

    Given that \displaystyle I_n=\displaystyle \int_0^a (a^2-x^2)^n \text{d}x where a is a positive constant,

    show that, for n>0, I_n=\dfrac{2na^2}{2n+1}I_{n-1}.
    This was a tricky one somewhat (I haven't spent all this time trying to do it lol, to clarify)
    Use difference of two squares, that's the starting point
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    (Original post by Takis6666)
    Sir i still didnt get why we put a 2π in the formula instead of one... in my mind a i see that with a single pi a full circle is formed 🤔?
    Oooh Sir? haha I'm a student. The 2pi is always there. If you have the edexcel FP3 textbook there's a short derivation of the formula if you're confused about where the 2pi comes from. It's page 82 but you can probably find a better and more complete version online. You don't need to know how to derive for the exam don't worry
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    (Original post by 13 1 20 8 42)
    This was a tricky one somewhat (I haven't spent all this time trying to do it lol, to clarify)
    Use difference of two squares, that's the starting point
    I don't see why you need to use the difference of two squares. I did by leaving it as it was and it took less than half a page.
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    (Original post by Kvothe the arcane)
    Learning Fp3 atm

    Can someone help me with a reduction formulae question from the book?

    You're given \displaystyle I_n=\int_0^a(a^2-x^2)^n \text{d}x.

    I tried IBP setting u=(a^2-x^2)^n but ended up having to deal with an \displaystyle \int_0^ax^2(a^2-x^2)^n \text{d}x integral and the power of x increases by 2 each time you try to IBP it so clearly that's a dead end.
    It's not a dead end. Try and split it up. If you're really stuck I have the solution but it's always better to try your best to solve it first.
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    (Original post by target21859)
    It's not a dead end. Try and split it up.
    I asked on whatsapp and Euclidean has done it if anyone's interested.


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    (Original post by Kvothe the arcane)
    I asked on whatsapp and Euclidean has done it if anyone's interested.

    Sent from my SM-G925F using Tapatalk
    Huh I did it a slightly different way. Name:  image.jpg
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    (Original post by target21859)
    Huh I did it a different way. Name:  image.jpg
Views: 125
Size:  507.9 KB
    The versatility of mathematics
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    (Original post by Euclidean)
    The versatility of mathematics
    True that. I've always done problems like that by putting it in a form that would merge with what's next to it and then add or subtract what I added.
 
 
 
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