123,206 reputation
479207
bio website math.ubc.ca/~israel
location Richmond, Canada
age
visits member for 3 years, 4 months
seen 7 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


4h
awarded  Nice Answer
20h
comment Laplace transform of noncentral chi-square distribution
Also it can't be right: $\Gamma(-r/2)$ will be undefined at all even positive integers $r$.
20h
answered Laplace transform of noncentral chi-square distribution
21h
comment Laplace transform of noncentral chi-square distribution
That's not the noncentral chi-square
22h
answered Complex numbers and their imaginary parts
2d
awarded  analysis
2d
answered solving system of equations(nonlinear)
2d
answered Prove two solutions of differential equation are the same
Jul
23
answered Definition and analyticity of $T^z$ where $T$ is a positive operator
Jul
23
comment Why does $\tan^{-1}(1)+\tan^{-1}(2)+\tan^{-1}(3)=\pi$?
Maple gave me a parametric solution which simplifies to $$\left\{ a={{\it \_Z1}}^{4}+2\,{{\it \_Z1}}^{3}+4\,{{\it \_Z1}}^{2}+3 \,{\it \_Z1}+3,b={{\it \_Z1}}^{2}+{\it \_Z1}+2,c=1+{\it \_Z1},d={\it \_Z1} \right\} $$
Jul
23
awarded  Nice Answer
Jul
23
answered Mathematical Intuition Behind Schizophrenic Numbers?
Jul
23
answered a question about sequence and series. prove $ \lim_{n \to \infty}( n\ln n)a_{n}=0$?
Jul
22
revised Optimum set partitioning with constraint
added 194 characters in body
Jul
22
revised Optimum set partitioning with constraint
added 194 characters in body
Jul
22
comment Optimum set partitioning with constraint
The question is nontrivial if $\sum_{i \in A} i \ge m$. For example with $m=5$ and $A = \{1,2,3,4\}$, an optimal solution is $\{1,3\},\{2\},\{4\}$.
Jul
22
answered Optimum set partitioning with constraint
Jul
22
answered Factoring in Maple
Jul
22
comment Choosing random marbles until one is divisible by $X$
The way you stated the problem, $X$ is always $1$: choose one marble and its number will certainly be divisible by $1$. If that's not what you mean, please explain what you do mean.
Jul
22
comment Solution of the Legendre's ODE using Frobenius Method
No. You can take $a_1$ to be anything. The recurrence then tells you want $a_3$ is in terms of $a_1$, what $a_5$ is in terms of $a_3$, etc.