Recent content by phucnguyen

Thanks Jbunniii and Dick for the help. I made my mistakes when concluding |K| = p2 too early. Here was how I came to it: Suppose ai phi(a)j = ak phi(a)l (where i, j, k, l are integers in range [0, p - 1]) That implies ai-k phi(a)j-l = e Because we assumed <a> and <phi(a)> were different...

Homework Statement This is question 30, section 2.5 from "Abstract Algebra 3rd edition" by Herstein. 2. Relevant information A subgroup H of group G is called characteristic if for all automorphisms phi of G, phi(H) is a subset of H. (I paraphrased this from question 29. I don't know...

Oh now I got it. Thank you very much!

Hi, I'm reading this piece from George Cain & James Harod's multivariable calculus material. Section 4.3, which is about Torsion, says this: I don't understand how he deduces dB/ds is perpendicular to T? Where did I get lost? Following the paragraph, it seems to me that T and N...

Hi Landau, Thanks for showing me the right way to do it. I mean I was learning the Jacobian. And before continuing with the lesson, I attempted to do it this way. I knew it was very likely that I would be wrong, but I tried it anyway, so that I could later find out where my thinking was wrong...

Hi, I'm learning to do double integration by changing variables and wondering about this. Suppose we have f(x, y) and want to find the volume under the surface over some bounded area in the xy plane. Say, I want to change the variables into u and v by: u = 3x - 2y v = x + y I need to...