20,135 reputation
12768
bio website
location
age
visits member for 2 years, 7 months
seen 6 mins ago

Oct
26
awarded  Popular Question
Oct
24
awarded  Nice Question
Oct
22
comment Differential equations: Solving a singular/nonlinear ODE using NDSolve
According to Maple, the system appears to be singular at the left point. It actually solved it analytical, with the trivial solution $y=0$. screen shot !Mathematica graphics (so basically your system is not well formed to solve) it suggested a mid-point numerical method. But I do not know now how to apply this in Mathematica NDSolve and it is there...
Oct
21
comment Setting up and solving system of equations
@SvendTveskæg use First command. updated.
Oct
21
revised Setting up and solving system of equations
remove {}
Oct
21
revised Setting up and solving system of equations
removed un-needed Expand[]
Oct
21
comment Setting up and solving system of equations
@SvendTveskæg Expand is not needed. I was doing something else before and left it there. Yes, you can remove the Expand command. It does not do anything. Will update. Thanks.
Oct
21
revised Setting up and solving system of equations
cleaned
Oct
21
answered Setting up and solving system of equations
Oct
20
comment How do I evaluate a symbolic integral involving Hermite polynomials?
Even after the correction in exp to Exp, it is not possible to get analytical solution. !Mathematica graphics after about 3 minutes trying... also Maple 17 not able to do it. To help find such syntax errors, I always look at the equation for the green colored symbols (or is this blue colored? I always mix green with blue). If the symbol is not black colored, then it means Mathematica does not know about it. You could have seen that exp was green colored, this means Mathematica does know about it.
Oct
20
revised Numerical solution of Bessel-like equation using NDSolve
clean
Oct
20
revised Numerical solution of Bessel-like equation using NDSolve
typos
Oct
20
reviewed Approve suggested edit on Number theory: Problem involving rational numbers
Oct
20
answered Numerical solution of Bessel-like equation using NDSolve
Oct
20
reviewed Approve suggested edit on FeynRules: Graph problem
Oct
19
revised Taking the LCM of algebraic expressions
added 61 characters in body
Oct
19
answered Taking the LCM of algebraic expressions
Oct
19
revised PDE Solving in mathematica
update
Oct
19
comment Animated Wave Propagation using Fourier & InverseFourier
any reason why you write InitialState instead of initialState and F2 instead of f2 etc..? It makes look like they are Mathematica own symbols and can be confusing.
Oct
19
comment PDE Solving in mathematica
@jtimz You can actually use the method of characteristics also to solve it? start by writing $\frac{dt}{1}=\frac{dr}{k}=\frac{du}{-2k\frac{u}{r}}$ and then $\frac{dr}{dt}=k$ or $r=tk+c_{1}$ or $r-tk=c_{1}$ and $\frac{du}{dt}=-2k\frac{u}{r}$ or $\frac{du}{u}=-2\frac{k}{r}dt$, hence $\ln u=-2\frac{k}{r}t+c_{2}$, hence $u=c_{2}e^{-2\frac{k}{r}t}$ So the the solution is function $f\left( r-tk,ue^{2\frac{k}{r}t}\right)$. I just forgot more of the details now. Need to look it more...separation of variables will also work....