# flapjackery

less info
reputation
6
bio website location age member for 2 years, 4 months seen 21 hours ago profile views 18

# 16 Accepts

 21h accepted Prove: If $A \subseteq B$ and $B \subseteq C$, then $A \subseteq C$. Jul18 accepted Prove $A \subset \emptyset \iff A = \emptyset$ Jul17 accepted Why does direct substitution work for limits? Dec20 accepted Please show $|\sin(n+1)x| = |\sin(nx+x)|$ Oct30 accepted What's the derivative $\frac{dE[F]}{dF_i}$ of this function $E[F] = |\frac{dF}{dx}|^2$? Jun12 accepted Evaluate the limit: $\lim_{(x,y,z)\to(0,0,0)}\frac{xy+yz^2+xz^2}{x^2+y^2+z^4}$ Jun10 accepted How to evaluate $\lim_{(x,y)\to(0,0)}\frac{y^2\sin^2x}{x^4+y^4}$ May26 accepted Find cumulative, marginal densities, moments for $f(x)=2,\le y \le x \le 1$ (multivariate) May25 accepted When deriving the multivariate normal distribution, please explain this limit May22 accepted Why is the PDF of this multivariate student t model $f(l)=Cl^{m-1}e^{-l^2/2}$ May21 accepted What is the proper way to compare discrete set of data to a continuous probability distribution? May21 accepted How would one rescale the variance and standard deviation of a set of data? May15 accepted Is it possible to determine if this matrix is ill-conditioned? May14 accepted Sign restriction on the Lagrange multiplier? Why? May14 accepted Does a quadratic necessarily have a root in this interval? Mar9 accepted Proof involving matrix inverse of: $\|A^{-1}\|_\infty \ge \frac{\|U^{-1}\|_\infty}{n}$