# mushin

Norway

 Dec 4 awarded Notable Question Nov 16 answered Fisher information of the Rayleigh distribution Nov 16 comment Fisher information of the Rayleigh distributionI did take them with respect to \$x_{i}\$'s. I will post the result asap. Nov 16 asked Fisher information of the Rayleigh distribution Sep 18 accepted Prove that a matrix is positive definite and symmetrical Sep 18 comment Prove that a matrix is positive definite and symmetricalThank you. I will try to work something out. One thing that is certain is that \$X^TX\$ is symmetric, because \$(X^TX)^T = X^T(X^T)^T = X^TX\$. By the Spectral theorem, it follows that \$X^TX\$ can be decomposed into matrices of eigenvectors and eigenvalues. Now I should be able to show \$v^TX^TXv \geq 0\$ for all vectors v I think. And thank you Karl (below) for providing the hint of transpose of \$X^TX\$ Sep 17 asked Prove that a matrix is positive definite and symmetrical Jul 2 awarded Curious May 22 awarded Popular Question May 7 comment Prove that the two integrals are equal with periodic functionPerfect, thank you. I need to work more with technical arguments like this rather than conceptual ones. May 7 accepted Prove that the two integrals are equal with periodic function May 6 asked Prove that the two integrals are equal with periodic function May 3 awarded Yearling May 3 awarded Yearling May 3 comment Evaluate limits by interpreting sums as integral sumsThank you, very good answer. May 3 accepted Evaluate limits by interpreting sums as integral sums May 2 comment Evaluate limits by interpreting sums as integral sumsWhat does it mean to interpret sums as integral sums. May 2 asked Evaluate limits by interpreting sums as integral sums Apr 5 comment Wrong way to use MVT to prove inequalityThank you all, I guess it is a good idea to REALLY understand the meaning of the MVT. I rushed to fast into doing problems. Apr 5 accepted Wrong way to use MVT to prove inequality