chwala's latest activity
-
chwala reacted to anuttarasammyak's post in the thread Prove that ## 4\tan^{-1}\left[\dfrac{1}{5}\right]- \tan^{-1}\left[\dfrac{1}{239}\right]= \dfrac{π}{4}## with
Like.
Arg function depends on direction not magnitude of complex number as you got the same result with him. He made use of it for easy... -
chwala replied to the thread Prove that ## 4\tan^{-1}\left[\dfrac{1}{5}\right]- \tan^{-1}\left[\dfrac{1}{239}\right]= \dfrac{π}{4}##.@Gavran ...you left out ##50## i.e in the denominator... can you see that? ought to be ...$$=\arg(0.5+0.5i)=\dfrac{π}{4}$$ Cheers. -
chwala reacted to Gavran's post in the thread Problem involving ordinary differential equation with
Like.
The substitution ## y_1=10^y ## simplifies the equation $$ 10^ydy=\frac{dx}{x\ln10} $$ to the equation ## dy_1=dx/x ##. The general case... -
chwala replied to the thread Undergrad Uniform convergence and pointwise convergence.For ##f_n(\theta)=e^{-n\sin \theta} ## on ##[0,π]## three cases to consider. Case 1 consider interior values, ##\sin \theta >0##... -
chwala reacted to pasmith's post in the thread Undergrad A counterexample to "the integral of the limit is the limit of the integral" with
Informative.
A generalization is to fix ##g: [0,1] \to \mathbb{R}## and let $$f_n : [0,1] \to \mathbb{R} : x \mapsto \begin{cases} ng(nx) & x < \frac... -
chwala replied to the thread Undergrad Uniform convergence and pointwise convergence.Will definitely look at it... -
chwala reacted to pasmith's post in the thread Undergrad A counterexample to "the integral of the limit is the limit of the integral" with
Like.
I was going to append this to @chwala's thread here, but thought it deserved a new thread. For ##n \geq 1##, define $$f_n : [0,1] \to... -
chwala replied to the thread Undergrad Uniform convergence and pointwise convergence.I meant for uniform convergence, this must hold ##\lim _{n→∞} sup |f_n (x) - f(x) | =0## and in our case, ##\lim _{n→∞} sup |f_n (x)... -
chwala replied to the thread Undergrad Uniform convergence and pointwise convergence.Thanks @WWGD , getting analysis slowly, in any case analysis is not that difficult as i had earlier thought, ... For uniform convergence... -
chwala reacted to WWGD's post in the thread Undergrad Uniform convergence and pointwise convergence with
Like.
Notice the limit function is discontinuous, which shows convergence isn't uniform. The limit of a sequence ##f_n \rightarrow f##... -
chwala reacted to pasmith's post in the thread Undergrad Uniform convergence and pointwise convergence with
Like.
Consider also ##e^{-n\sin \theta}## for ##\theta \in [0, \pi]##. -
chwala reacted to fresh_42's post in the thread Undergrad Uniform convergence and pointwise convergence with
Like.
You should try to prove the non-uniformness of the two examples @WWGD and I gave to see that you cannot choose N independently of the... -
chwala replied to the thread Undergrad Uniform convergence and pointwise convergence.clearer now, For ##f(x)=x^n ## on ##[0,1]## three cases to consider. Case 1 consider ##0 ≤x <1## ##x^n → 0, ∀ 0 ≤x <1 ## further...