Tunococ
Reputation
7,044
Top tag
Next privilege 10,000 Rep.
Access moderator tools
Badges
13 22
Newest
Impact
~173k people reached

• 0 helpful flags
• 187 votes cast

# 1,543 Actions

 Feb 10 comment Prove that $a+\frac{1}{b}>2$ or $b+\frac{1}{a}>2$ for two strict positive numbers @ByronSchmuland Did the answer get vandalized? Feb 10 answered Matrices and diagonalization. Feb 9 comment convolution is well-defined and differentiable for continuous $f$ and differentiable $g$ with compact support I think the term "well-defined" here has a different meaning. I think you're supposed to show that the integral is finite for every $x$. Feb 9 comment Differentiability of PDE with respect to parameters Oh I understand what you mean now. In that case, I tend to believe the answer is positive. You have the same differential operator acting on $u$ and $\frac{\partial u}{\partial y}$ (and all its higher $y$ derivatives), and the non-homogeneous term seems to possess the same type of regularity. Feb 9 comment Differentiability of PDE with respect to parameters I'm not sure what the second equation means. (Are there typos? Zero on the left-hand side maybe?) Anyway, I suspect that smoothness of $a_{\alpha}$ with respect to $y$ might not be enough. I believe zeros of some $a_{\alpha}$ might cause irregularity, but I could be wrong. Feb 9 comment Injectivity in the zero homology You can write up your own answer and accept it. (You can make it community's answer too, I believe.) Feb 9 comment Write expressions w/out quantifiers (convert to AND/OR expressions) I think you're thinking about the right method, but for a), there's a mistake in the first pair of brackets, and in c), you should have only three terms. Feb 9 comment Finding the maximum value of a divergent series If you can prove that the sum is smaller than a particular value, then it will converge because the sequence of partial sums is monotonically increasing. The question that you mentioned involves a finite sum. Feb 9 comment Appropriate distribution for set of probabilities $p_1 ,…, p_n$ How about uniform distribution in the given region? Feb 9 comment Why would an equation switch signs when something becomes independent of time? (Traffic Flow) I think you might have misread something. Equation (10) involves $\frac{\partial q}{\partial x}$, not $\frac{\partial\rho}{\partial t}$ Feb 9 comment Conditional pdf of a random variable that is a function of other random variables The pdf of $g(x, Z)$ will be related to $f(y \mid x)$, but not necessarily equal. You can even take a simpler example, like $Y = 2Z$. Feb 9 comment If a and b are negative , then can we use the same method we are taught for solving the equation y'' + ay' + by=0 , @Leth I think you must have missed some details in those statements that you remembered. For example, maybe it was more like what macroland said? Feb 9 comment How to derive the equation of tangent to an arbitrarily point on a ellipse? I'm not sure if you understand implicit differentiation correctly but your notation seems off. Your $\frac{d}{dx}$ should be just $dx$ (and the same with $dy$). Feb 9 answered Eigenvector of a matrix of ones associated with $\lambda =0$ Feb 9 comment If a and b are negative , then can we use the same method we are taught for solving the equation y'' + ay' + by=0 , @Leth Those methods will work regardless of the signs of $a$ and $b$. (What makes you think they might not work?) Feb 9 comment If a and b are negative , then can we use the same method we are taught for solving the equation y'' + ay' + by=0 , What method were you taught? The method I know doesn't really care much about the signs of $a$ and $b$. Feb 9 comment Functions between metric spaces (and how they relate to closures of sets) Yes. It has something to do with the fact that $X$ is not compact. Feb 8 answered Vanishing Integral of a differential form without using Stokes' Theorem Feb 8 comment Solve this system of nonlinear differential equations The fraction can be simplified to a constant, namely $\frac{k_1}{k_2}$. Feb 8 revised Chance of drawing 4 red marbles out of a big bag. added 428 characters in body