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Further Mathematics: Post your doubts here!

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I dont think it was that hard... I hope it to be as low as possible. but by observing the trend it would be 80s
yeah :/ ... it's strange tho.. an A in physics is usually around 55-60% and for further maths it's 80%
 
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So yeah. Yesterday's paper was fine. like I'm on course for a B :p (which is think is fine for Fmath)
Okay couple of doubts for tomorrows papers:
Formulae, mean and variance for Geometeric distributions, negative exponential and poisson.
It's a bit urgent LOL :p
 
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May june 08 question numbere of 11 second part (stats question)
how is the expected frequency obtained?? really driving me crazy..
http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Mathematics - Further (9231)/9231_s08_qp_2.pdf
It's simple. Once you have p= 0.5435, assume a geometric distribution and calculate p(X=n) for n=1,2,3,4,5... p(x>=6) can be found using 1-p(x<6). Then,
E(x)=np, so, for example, E(X=1)= 100p(X=1). Just do that for all of them.
 
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can anyone give me any notes or nything that might help me understand ths Y=X^3!
pls urgent!!
 
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It's simple. Once you have p= 0.5435, assume a geometric distribution and calculate p(X=n) for n=1,2,3,4,5... p(x>=6) can be found using 1-p(x<6). Then,
E(x)=np, so, for example, E(X=1)= 100p(X=1). Just do that for all of them.

thnks bro! undersood!
 
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Why are we neglecting gravity in Question 2 May/June Paper 2-1 2011? Aren't we supposed to account for all forces?
 
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Are the books for Mathematics and Further Mathematics the same ?
I don't think so. A-level Mathematics consists of Pure Mathematics 1, 2 & 3, Mechanics 1 and Statistics 1; Futher Mathematics includes Further Pure Mathematics (which is different from the Pure Mathematics book and, obviously, much thinker and heavier :cry: ), Mechanics 2, 3 & 4, and "A Concise Course of Advanced Statistics". (I would say the book is not concise at all... )
 
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Hi guys, could anyone help me out with Question 8, part 2 of this paper? http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Mathematics - Further (9231)/9231_s06_qp_1.pdf

I've always hated differential equations. Any help would be greatly appreciated :)

Edit: Also, Question 11, the one after 'either'. Show that, in fact the equation..., and the question directly following that.
Q8) After you've obtained the general solution, which is: y = e^(-3t) (B cos 4t + C sin 4t) + 5e^(-3t) , make use of the values given.
When t = 0, y = 8. Put this in your general solution to get B = 3.
Differentiate your general solution. It should be: dy/dt = - 3e^(-3t) (B cos 4t + C sin 4t) + e^(-3t) (-4B sin 4t + 4C cos 4t) - 15 e^(-3t).
When t = 0, dy/dt = -8. Insert this above to get C = 4.

Now you're particular solution is: y = e^(-3t) (3 cos 4t + 4 sin 4t) + 5e^(-3t)
=> ye^(3t) = 3 cos 4t + 4 sin 4t + 5
Using the compound angle identity, you can write this as: ye^(3t) = 5 cos (4t + E) + 5. You could find E but that's not relevant to the question.
Since t can take any value, min. value of ye^(3t) = 5(-1) + 5 = 0
Max. value of ye^(3t) = 5(1) + 5 = 10
So, 0 ≤ ye^(3t) ≤ 10 for all t.
 
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Edit: Also, Question 11, the one after 'either'. Show that, in fact the equation..., and the question directly following that.

I don't think I can give a better explanation than the examiner report. It is a simple Mathematics P3 concept, if a sign changes between two integers when substituted in a polynomial, a root lies between them. So you may just put in the values 0,-1,-2 and -3 in the given equation and show that the sign changes twice in this interval so 2 roots lie in the interval which have to be real.

For the second part remember that the product of a pair of conjugate complex roots is equal to the square of the modulus of one of the roots. This is a universal rule. Here I have illustrated it:

s06either.png
 
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