Alex Becker
Reputation
42,909
88/100 score
 May 16 comment Can the norm of a non-algebraic integer be an integer? When you say non-algebraic integer, do you mean an algebraic element of the extension which is not an algebraic integer? May 16 comment Breaking even: is there a point where you can always profit? @nononono $\frac{9}{2}=1+y=1+\frac{7}{2}$. May 16 comment Conditional Random Variable and Iterated Expectation @sandra Here $A$ is not a random variable, it is an event. May 16 revised PUGS is a rectangle. If the equation of PU is $y=\frac{2}{3x} + 4$. What is the slope of SP? fixed error introduced by previous edit May 15 awarded Nice Question May 15 comment Calculating fundamental group and homology group to prove not homeomorphic to each other @MarianoSuárez-Alvarez Yes, thanks. May 15 revised Calculating fundamental group and homology group to prove not homeomorphic to each other added 1 character in body May 15 answered Calculating fundamental group and homology group to prove not homeomorphic to each other May 15 comment Random nonegative solution of multivariate linear Diophantine equation Do you just need a solution, or do you need an algorithm which is equally likely to produce any of the solutions? May 15 comment We can tell that f is not a translation or glide reflection (hence, it must be a rotation). How? Are we assuming that $f$ is an isometry? May 15 comment Is this math valid? @MJD On the other hand, it is not unreasonable to assume the worst-case scenario in questions about regulation, esp. public health. May 15 answered A matrix $M$ that commutes with any matrix is of the form $M=\alpha I$ May 15 comment Is this math valid? I think the assumption is that the milk contains 100 micrograms per kilogram. Since two cups is about half of a kilogram, it would then contain about 50 micrograms. May 14 comment Help with proving that the transpose of the product of any number of matrices is equal to the product of their transposes in reverse @1west Try using induction. We have $A^TB^TC^T=(BA)^TC^T=(C(BA))^T=(CBA)^T$. Proceed in the same manner. May 14 comment Do circles exist $\pi$ is irrational, so its decimal expansion never ends, but that doesn't mean it doesn't exist. May 14 comment Convergence of the series $\sum \frac{(-1)^{\sqrt{n}}}{n}.$ I'm a little confused. The real-analysis tag and $<$ sign seem to imply you're working in $\mathbb R$, but generally $(-21)^{\sqrt n}$ will not be real. May 13 comment Find the volume of a cone whose length of its side is $R$ I have merged this question with your previous one. May 13 comment True or False: $i^2 = -1$, $\mathbb{C} = \mathbb{R}^2$ @Optional I think this answers the part of your question that makes sense. If you understand this answer, then I can't understand what your remaining question is. May 9 comment finite field extension and normality What definition of normality are you using? May 9 comment can I show this set is closed? @DavidMitra I would go so far as to call this a duplicate of that question. Do you agree?