Recent content by jashua

  1. J

    Uniformly Most Powerful Tests.

    Why do you need to obtain a binomial distribution? The question does not require this.
  2. J

    Calculating the Probability of K=3 When Flipping a Coin 6 Times

    Can you give your reasoning? May I ask what your computational result is?
  3. J

    Calculating the Probability of K=3 When Flipping a Coin 6 Times

    Your answer finds P(K>=3), but OP asks for P(K=3).
  4. J

    Calculating the Probability of K=3 When Flipping a Coin 6 Times

    I think you mean "...we will have 3 crowns...". You will have 3 crowns after flipping a coin 6 times in (6 choose 3) different ways, right? And you get a crown with probability p = 0.3, which implies that you will not have a crown with probability q = 1-p = 0.7. Suppose one of the experiments...
  5. J

    Combinations/Permutations of Seating at a Circular Table

    Think that you place 9 women around the circular table. As the question requires the number of circular permutations, there are (9-1)! ways to place 9 women. Now there are 9 spaces to place 6 men such that none of these 6 men sit next to each other. Then, just find the number of ways to place 6...
  6. J

    Show complex summation property

    It seems z = 1 + ik, where k is an integer. It is also interesting to notice that f(z) is periodic with 1, as mfb has said. Then the relation between f(z) and f(z+i) must hold for z = r + ik, where both r and k are integers.
  7. J

    Existence of Natural Number n for f(x+n)=f(x) like cos+2pi

    As f(x)=f(x+3)f(x-3)=f(x+3)f(x)f(x-6), we have f(x+3)f(x-6)=1 (ignoring that f(x)=0). Then, f(x)f(x-9)=1. Similarly, we find that f(x)f(x+9)=1. As a result, f(x+9)=f(x-9), and so, f(x)=f(x+18). Thus, n=18.
  8. J

    Numbered balls and replacement

    There are 17 possible ways you choose 2 balls with replacement such that Z=max(X,Y)=9. The number of all possible ways you choose 2 balls with replacement is 100. Now you should be able to find the answer.
  9. J

    Finding values for a linearly independent subset

    As you have written, let a\begin{pmatrix} 1 & 2\\ 1 & 0 \end{pmatrix}+b \begin{pmatrix} 3 & 7\\ 0 & 0 \end{pmatrix}+c \begin{pmatrix} 2 & 6\\ \alpha & 0 \end{pmatrix}= \begin{pmatrix} 0 & 0\\ 0 & 0 \end{pmatrix} Then, \begin{pmatrix} a+3b+2c & 2a+7b+6c\\ a+c\alpha & 0 \end{pmatrix} =...
  10. J

    Definite integral of gaussian

    Ray, thank you very much for your detailed answer.
  11. J

    Calculating number of character combinations in password

    I think we can formulize your solution as follows: Let n(A) : # of passwords without any number, n(B): # of passwords without any letter, n(C): # of passwords without any symbol, n(S): # of passwords in the full set. Then, we calculate n(S)-n(A\cup B\cup C), where n(A\cup B\cup...
  12. J

    Expected value of complex gaussian

    The lower limit does not become 0 if you expand the expression. I mean the linear substitution changes the lower limit.
  13. J

    Relationship between Fourier and Lpalace transforms

    A signal has its Fourier transform if and only if its ROC of Laplace transform contains the imaginary axis s=jw. The statement that you give is valid only for the right-hand sided signals for which the ROC is the right hand side of the poles. Fourier transform and Laplace transfrom (whether...
  14. J

    Integral Approximation: Tau <<T

    If that is the final version of the integral then it is enough to say that the equality holds.
  15. J

    Integral Approximation: Tau <<T

    Your assumtion is not enough to show one of the relations is true. It seems you need to show that the integrand is periodic with T/(1+\alpha).
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