martini
Reputation
58,209
88/100 score
 Mar 22 comment Mapping, relations and logical expressions What do you mean by the set $3$? Usually, one has $3 = \{0,1,2\}$, so $\alpha \subseteq 4 \times 4$... Mar 22 comment Find $b$ such that $\log_b(x)$ and $\log_b(y)$ are integers. @SimpleArt As both equal $b$. Mar 22 answered Find $b$ such that $\log_b(x)$ and $\log_b(y)$ are integers. Mar 22 answered Exercise on separable Hilbert spaces and orthonormal system Mar 22 comment Two congruent segments does have the same length? If I recall correctly, we define length in axiomatic geometry by taking the segments modulo congruence. That is the set of possible length is $$L = \{\text{segments}\}/\cong$$ and the length of a particular segment is the class of it modulo congruence: Hence, obviously, by definition of length, not of congruence, your claim is true. Mar 22 comment Prove the product of two $W_0^{1,p}$ functions gives another $W_0^{1,p}$ function if $p>n$ It is not true that $$\def\n#1{\left\|#1\right\|_{W^{1,p}}}\n{uv} \le \n u \n v$$ Mar 22 comment convolution: how can I show that $(y*f)'(t) = (y'*f)(t) + y(0)f(t)$ I did not leave off any steps and added something regarding your mistakes. Mar 22 revised convolution: how can I show that $(y*f)'(t) = (y'*f)(t) + y(0)f(t)$ added 596 characters in body Mar 22 reviewed Close Derivative functions. Mar 22 reviewed Leave Open Is this function differentiable at $x=0$? Mar 22 reviewed Leave Open is there a holomorphic function defined on a neigborhood of $0$ such that $f(\frac{1}{n})=\frac{1}{1+n}$ Mar 22 reviewed Leave Open Correlation in a series of 1s and 0s Mar 22 reviewed Leave Open Use a proof by case to show that $\gcd (m+n,mn)-\gcd (m,n)$ is even for all integers $m$ and $n$. Mar 22 reviewed Close Count the license plates possible with 4 letters and 2 digits Mar 22 reviewed Close Finding the limit of the sequence $\left\{ {{a_n}} \right\}$ Mar 22 comment Finding the limit of the sequence $\left\{ {{a_n}} \right\}$ Possible duplicate of $\lim_{p\to \infty}\Vert f\Vert_{p}=\Vert f\Vert_{\infty}$? Mar 22 reviewed Leave Open noncommutative ring with unity.. Mar 22 reviewed Leave Open a minoration of $P(X>x)$ with $X~N(0,1)$ Mar 22 comment Laplace Transform: $g(x)=a\sin(x)+\int_0^x \sin(x-u)g(u) du$ @AlexM. This integral is a convolution of functions $[0,\infty) \to \mathbf R$, for $\int_0^\infty f(t)g(x-t) \,dt$ is not well-defined for such functions, if as $g(x-t)$ only makes sense for $t \le x$. So the convolution of such functions is usually defined as $$(f*g)(x) = \int_0^x f(t)g(x-t) \,dt$$ Mar 22 answered convolution: how can I show that $(y*f)'(t) = (y'*f)(t) + y(0)f(t)$