130,030 reputation
587222
bio website math.ubc.ca/~israel
location Richmond, Canada
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visits member for 3 years, 6 months
seen 6 hours ago

I'm an Emeritus Associate Professor of Mathematics at University of British Columbia and an Optimization Algorithms Researcher at D-Wave Systems in Burnaby BC


7h
answered Does an inverse Laplace transform for $\hat{F}(s)=e^{-is}$ exist? If not, why?
8h
comment What does the Fundamental Theorem of Algebra say about…
Your first answer was not an answer to the question, and was incorrect.
9h
answered What does the Fundamental Theorem of Algebra say about…
13h
comment Can the furthest-neighbor algorithm outdo the nearest-neighbor?
Oops, sorry, not so easy.
14h
comment Can the furthest-neighbor algorithm outdo the nearest-neighbor?
Do you want to still have the property that the nearest-neighbor algorithm gives the worst possible result? If not, it's easy.
17h
answered Get unknown value in discrete random variable
17h
answered Help with finding an analytic function on a given domain
20h
answered Determining a Differential equation, related to Legendre
20h
answered Can this recursive summation function be simplified?
1d
comment Integration with quadratic square root
Maple also doesn't find a closed form, even in special cases such as $a=c=1$, $b=0$. I would be quite surprised if a closed form existed.
1d
answered Is it even possible to find the variance of this moment generating function?
1d
answered Limit when $n\rightarrow\infty$ of $\text{sgn}(\sin(2^n \pi x))$ with $x\in(0,1)$ fixed.
1d
comment How can I use a Gamma Random Variable to Aproach the Expected value of a exponential random variable function?
Now, the divergence is rather slow, so in a simulation it may not be very easy to see that it diverges, but nevertheless it really does diverge.
1d
comment How can I use a Gamma Random Variable to Aproach the Expected value of a exponential random variable function?
The density for an exponential random variable of mean $1$ is $\exp(-t)$. So $$ E\left[\dfrac{e^x}{x+1}\right] = \int_0^\infty \dfrac{e^t}{t+1} e^{-t}\; dt = \int_0^\infty \dfrac{dt}{t+1} = \infty$$
1d
comment How can I use a Gamma Random Variable to Aproach the Expected value of a exponential random variable function?
No!!! You can not use simulation or any other method to "approximate" something that does not exist.
1d
revised transpose and inverse multiplication
added 4 characters in body
1d
answered transpose and inverse multiplication
1d
answered How can I use a Gamma Random Variable to Aproach the Expected value of a exponential random variable function?
1d
answered How does one prove that elements of the Borel set are regular?
1d
answered Necessary and Sufficient Conditions for $f_{xy} = f_{yx}$