Recent content by glacier302
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Graduate Proving Sum of 2 Indep. Cauchy RVs is Cauchy
Given the fact that X and Y are independent Cauchy random variables, I want to show that Z = X+Y is also a Cauchy random variable. I am given that X and Y are independent and identically distributed (both Cauchy), with density function f(x) = 1/(∏(1+x2)) . I also use the fact the...- glacier302
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- Cauchy Independent Random Random variables Statistics Sum Variables
- Replies: 2
- Forum: Set Theory, Logic, Probability, Statistics
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Proving Cauchy Density Function for Z = X+Y
Homework Statement Let X and Y be independent random variables each having the Cauchy density function f(x)=1/(∏(1+x2)), and let Z = X+Y. Show that Z also has a Cauchy density function. Homework Equations Density function for X and Y is f(x)=1/(∏(1+x2)) . Convolution integral =...- glacier302
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- Cauchy Density Density function Function
- Replies: 1
- Forum: Calculus and Beyond Homework Help
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MATLAB How to write Matlab code for a multivariate Beta distribution
Maybe it would help if I provided more information about the problem: I'm working on a Gibbs sampler problem. For the regular Gibbs sampler, I used beta distributions to sample the probabilities p and q. I have a vector I that I'm updating at each iteration, which depends on the current...- glacier302
- Post #2
- Forum: MATLAB, Maple, Mathematica, LaTeX
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MATLAB How to write Matlab code for a multivariate Beta distribution
Hello, I am working on a problem in which I first sample two unknown probabilities, p and q, from Beta distributions, and then I want to sample both of them at the same time from a multivariate Beta distribution. This is the code that I have for sampling p and q individually from Beta...- glacier302
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- Beta Code Distribution Matlab Matlab code Multivariate
- Replies: 1
- Forum: MATLAB, Maple, Mathematica, LaTeX
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Product Measures, Fubini's Theorem
Never mind, I think I've got it. Since I want to solve the integral ∫g(x)dx from x=0 to x=a = ∫∫(1/t)f(t)dtdx, inner integral from t=x to t=a, outer integral from x=0 to x=a, the function is bounded by the curves t=x, t=a, x=0, and x=a. Another way of writing this is that the function is...- glacier302
- Post #2
- Forum: Calculus and Beyond Homework Help
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Product Measures, Fubini's Theorem
Homework Statement Let f be Lebesgue integrable on [0,a], and define g(x) = ∫(1/t)f(t)dt , lower integrand limit = x, upper integrand limit = a. Prove that g is integrable on [0,a], and that ∫f(x)dx = ∫g(x)dx . Homework Equations In the previous problem, I showed that if if f and g are...- glacier302
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- Product Theorem
- Replies: 1
- Forum: Calculus and Beyond Homework Help
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Graduate Abs Continuous Function w/ Unbounded Derivative on [a,b]
Aha. Thank you! I knew that if a bounded function is Reimann integrable then the Reimann integral and the Lebesgue integral of the function are equal. However, I always forget that this can be extended to unbounded functions as long as the Reimann integral is finite. Thanks again!- glacier302
- Post #5
- Forum: Calculus
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Graduate Abs Continuous Function w/ Unbounded Derivative on [a,b]
Thank you for your help. One question: How I do know that the derivative of that function is integrable? If f' were bounded, then the fact that it is only discontinuous at x = 0 would make f' Reimann integrable, and Reimann integrability implies Lebesgue integrability for bounded functions. But...- glacier302
- Post #3
- Forum: Calculus
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Graduate Abs Continuous Function w/ Unbounded Derivative on [a,b]
What is an example of an absolutely continuous function on [a,b] whose derivative is unbounded? I know that the function f: [-1,1] defined by f(x) = x^2sin(1/x^2) for x ≠ 0, f(0) = 0 is continuous and its derivative f'(x) = 2xsin(1/x^2)-2/xcos(1/x^2) for x ≠ 0, f'(0) = 0 is unbounded on...- glacier302
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- Continuous Derivative Example Function
- Replies: 4
- Forum: Calculus
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Absolutely continuous functions and sets of measure 0.
Homework Statement Prove that if f: [a,b] -> R is absolutely continuous, and E ∁ [a,b] has measure zero, then f(E) has measure zero. Homework Equations A function f: [a,b] -> R is absolutely continuous if for every ε > 0 there is an δ > 0 such that for every finite sequence {(xj,xj')}...- glacier302
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- Continuous Continuous functions Functions Measure Sets
- Replies: 1
- Forum: Calculus and Beyond Homework Help
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Measurability of a function f which is discontinuous only on a set of measure 0.
Homework Statement Let f:[a,b] -> R be a bounded function, and let D be the set of points at which f is not continuous. (a) Prove that D is a countable union of closed sets. (b) Prove that if m(D) = 0, then f is measurable. Homework Equations Of(x) = lim(ε->0)(sup f(y) - inf...- glacier302
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- Function Measure Set
- Replies: 1
- Forum: Calculus and Beyond Homework Help
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Analysis - How many numbers in the interval [0,1) contain 5 consecutive 5's?
Homework Statement Let E be the set of points in [0,1) whose decimal expansion contains somewhere the block 55555. Find the measure of E. Homework Equations The Attempt at a Solution I have a feeling that in order to find the measure of E, I should find the measure of the...- glacier302
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- Analysis Interval Numbers
- Replies: 1
- Forum: Calculus and Beyond Homework Help
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Real Variables: Measurability of {x: x∈An i.o.}
I think I figured it out. Thank you!- glacier302
- Post #3
- Forum: Calculus and Beyond Homework Help
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Real Variables: Measurability of {x: x∈An i.o.}
Homework Statement Let An, n = 1,2,..., be a sequence of measurable sets. Let E = {x: x∈An i.o.}. (a) Prove that E is a measurable set. (b) Prove that m(E) = 0 if ∑m(An) < ∞ Homework Equations A point x is said to be in An infinitely often (i.o.) if there is an infinite...- glacier302
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- Variables
- Replies: 2
- Forum: Calculus and Beyond Homework Help
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Find the general solution of dX/dt = AX(t) for the given 3x3 matrix A.
Hello, Thank you very much for your help. I see now that using matrix exponentials is not the easiest way to solve this problem. Thanks again! : )- glacier302
- Post #3
- Forum: Calculus and Beyond Homework Help