1,244 reputation
416
bio website
location
age
visits member for 1 year, 8 months
seen 1 hour ago

19h
asked a custom designed cutoff function whose derivative is bounded above.
2d
comment How to find the derivative of the flow of an autonomous differential equation with respect to $x$
Thanks for the hints. What I wanted to show was $\eta(x)$ was $C^1$. May be there is an indirect way to show this without actually 'computing' the derivative under the integral sign.
Aug
26
revised How to find the derivative of the flow of an autonomous differential equation with respect to $x$
added more clarification and improved latex
Aug
26
reviewed Approve suggested edit on How to find the derivative of the flow of an autonomous differential equation with respect to $x$
Aug
26
comment How to find the derivative of the flow of an autonomous differential equation with respect to $x$
Yes, this is something that has always bothered me. Is $x$ fixed or not?. Why do they use the same letter $x$ in the differential equation and for the initial condition?. I am sure there is a good reason, but I am completely confused now.
Aug
26
revised How to find the derivative of the flow of an autonomous differential equation with respect to $x$
added clarification
Aug
26
asked How to find the derivative of the flow of an autonomous differential equation with respect to $x$
Aug
25
comment Let $\eta (x)=\int_0^\infty e^{at}\xi(\phi_t(x)) dt$ then $\eta$ is a $C^1$ function
Thanks for your comment. Since $\xi$ vanishes outside of $(-r,r)$ can I integrate $\eta$ from $0$ to $r$ instead of from $0$ to $\infty$?
Aug
24
revised Let $\eta (x)=\int_0^\infty e^{at}\xi(\phi_t(x)) dt$ then $\eta$ is a $C^1$ function
added latex
Aug
24
asked Let $\eta (x)=\int_0^\infty e^{at}\xi(\phi_t(x)) dt$ then $\eta$ is a $C^1$ function
Aug
24
comment Why the limit of $\frac{\sin(x)}{x}$ as $x$ approaches 0 is 1?
Read Robjohn's answer here
Aug
24
revised How do I factor this quadratic?
improved formatting
Aug
24
suggested suggested edit on How do I factor this quadratic?
Aug
24
comment Every solution of the system is attracted to the center manifold
Thanks for your answer. is this image from a book you are using?. Would you mind telling me what it is?. It would be helpful If I could see some more examples.
Aug
22
asked Every solution of the system is attracted to the center manifold
Aug
21
accepted The system $\dot{x}=x^2$, $\dot y=-y$, has infinitely many (local) center manifolds
Aug
21
comment The system $\dot{x}=x^2$, $\dot y=-y$, has infinitely many (local) center manifolds
Makes sense.Thanks for the explanation. Do you mind telling me what you used to draw the phase portrait diagram?.
Aug
21
comment portfolio optimisation
Perhaps you would want to ask this question on quant stackexchange as well.
Aug
21
comment Reference for Generalized Eigenvectors
You are probably looking for a reference book. Matrix Analysis by Horn and Johnson might help.
Aug
21
asked The system $\dot{x}=x^2$, $\dot y=-y$, has infinitely many (local) center manifolds