Hikari Clover
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- May 26, 2007
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- HSC
- 2007
NEW polynomials Qs+ polynomial Qs
a bag contains 6 white cubes and 4 black cubes. A cube is drawn out, its colour noted and then replaced. this process is repeated 6 times.
a)what is the probability that at least 4 white cubes are withdrawn?
b)find the number of white cubes that is most likely to be withdrawn?
answer:
a)0.54432
b)4
i have no problem with part a
but for part b ,isn't it meant u have to find its greatest term in binomial expansion (3/5+2/5)^6 ,but it doesn"t work!!the answer i got is 2......
could any1 explain to me what i missing?
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if A is the sum of the odd terms and B is the sum of the even terms in the expansion of (x+a)^n, prove that A^2-B^2=(x^2-a^2)^n
a bag contains 6 white cubes and 4 black cubes. A cube is drawn out, its colour noted and then replaced. this process is repeated 6 times.
a)what is the probability that at least 4 white cubes are withdrawn?
b)find the number of white cubes that is most likely to be withdrawn?
answer:
a)0.54432
b)4
i have no problem with part a
but for part b ,isn't it meant u have to find its greatest term in binomial expansion (3/5+2/5)^6 ,but it doesn"t work!!the answer i got is 2......
could any1 explain to me what i missing?
--------------------------------------------------------------------------------
if A is the sum of the odd terms and B is the sum of the even terms in the expansion of (x+a)^n, prove that A^2-B^2=(x^2-a^2)^n
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