1,904 reputation
1541
bio website
location Aalto University, Finland
age 25
visits member for 3 years, 6 months
seen Jul 4 at 11:54

profile for hhh on Stack Exchange, a network of free, community-driven Q&A sites

Great!

3 Principles of Success (Harford)

  1. Seek out and try new things.

  2. When trying something new, do it on a scale where failure is survivable.

  3. Seek out feedback (to determine your level of success) and learn from your mistakes as you go along.

P.s. 6 ways to kill creativity, contact in forename@surname.com.


Jul
2
awarded  Curious
Jul
2
awarded  Inquisitive
Jun
17
awarded  Popular Question
May
17
awarded  Notable Question
May
15
awarded  Popular Question
May
12
awarded  Notable Question
May
7
comment Difference between Variation of Calculus problems and Control Theory problems?
Intriguing, big thanks! I like the references! +1
May
5
asked Difference between Variation of Calculus problems and Control Theory problems?
May
5
revised How are Hamilton function and Hamilton-Jacobian-Bellman function related to each other?
added 248 characters in body
May
5
asked How are Hamilton function and Hamilton-Jacobian-Bellman function related to each other?
May
5
revised Solution to the differential equation $\frac{1}{2}\dot K-K^2+K=0$?
fixed an err
May
5
comment Solution to the differential equation $\frac{1}{2}\dot K-K^2+K=0$?
@Jean-ClaudeArbaut I could consider a bit simpler problem where $K>1$ to get rid of the absolute values. Even then the solution in My solution does not match the given solution, why?
May
5
comment Solution to the differential equation $\frac{1}{2}\dot K-K^2+K=0$?
@Jean-ClaudeArbaut Excellent point! It is a mistake -- wait I haven't considered absolute values deeply enough probably -- there is no restriction for K. $T$ is a constant in My Solution.
May
5
asked Solution to the differential equation $\frac{1}{2}\dot K-K^2+K=0$?
Apr
29
comment Largest value in the functional $\int_0^\infty e^{-rt}( x^2+2x+\dot x^2)dt$?
Yes I finally understood it. Thank you for the attention! It required some patience :)
Apr
29
comment Solution to $1+x+r\dot x -\ddot x=0$ when $x(0)=1$: combination of monomials with solutions to the characteristic equation?
Thank you! Got it now clear :)
Apr
29
accepted Solution to $1+x+r\dot x -\ddot x=0$ when $x(0)=1$: combination of monomials with solutions to the characteristic equation?
Apr
29
comment Solution to $1+x+r\dot x -\ddot x=0$ when $x(0)=1$: combination of monomials with solutions to the characteristic equation?
Same time! $2e^{0.5(r+\sqrt{4+r^2})t}+C_1e^{0.5(r-\sqrt{4+r^2})t}-C_1e^{0.5(r+\sqrt{4+r^2})‌​‌​t}=(2-C_1)e^{0.5(r+\sqrt{4+r^2})t}+C_1e^{0.5(r-\sqrt{4+r^2})t}=C_2e^{0.5(r+\sqr‌​t{4+r^2})t}+C_1e^{0.5(r-\sqrt{4+r^2})t}$. Bingo, Thank you! :D
Apr
29
comment Solution to $1+x+r\dot x -\ddot x=0$ when $x(0)=1$: combination of monomials with solutions to the characteristic equation?
How is this $2e^{0.5(r+\sqrt{4+r^2})t}+C_1e^{0.5(r-\sqrt{4+r^2})t}-C_1e^{0.5(r+\sqrt{4+r^2})‌​t}$ the homogenous solution? I can understand your ideas but not yet the idea here.
Apr
29
comment Solution to $1+x+r\dot x -\ddot x=0$ when $x(0)=1$: combination of monomials with solutions to the characteristic equation?
Spot-on, messed up homogenous and non-homegenous cases +1 for it. I can understand so far but not yet $2e^{0.5(r+\sqrt{4+r^2})t}+C_1e^{0.5(r-\sqrt{4+r^2})t}-C_1e^{0.5(r+\sqrt{4+r^2})‌​t}$ in $x^*_2=2e^{0.5(r+\sqrt{4+r^2})t}+C_1e^{0.5(r-\sqrt{4+r^2})t}-C_1e^{0.5(r+\sqrt{4‌​+r^2})t}-1$. I would write it as Claude i.e. $x(t)=c_1 e^{\frac{1}{2} \left(r-\sqrt{r^2+4}\right) t}+c_2 e^{\frac{1}{2} \left(\sqrt{r^2+4}+r\right) t}-1$.