### Questions (634)

 10 basic difference between canonical isomorphism and isomorphims 7 What is the most common and appropriate definition of tensor? [closed] 5 Can we expand “induction principle” to a partial order $(X, \leq)$? 5 Show that $\mathbb{Q}_3(i)$ is an unramified extension 5 Show that $h(x)=\max \{f(x,y) : y \in [0,1] \}$ is continuous

### Reputation (6,151)

 +25 Find the argument of $z = {\left( {2 + i} \right)^{3i}}$ +15 Geometry of $GL_n(F)$ inside $M_n(F)$ +10 Draw a 3-dimensional vector $v$ by an arrow and show where to find all $w$'s satisfying $v \cdot w<0$ +10 what is the basic difference between an algebra over a field and a vector space over a field?

 5 Where does $\pi^2$ appear spontaneously within Physical Phenomenon and Mathematics Equations? 5 If an $R$-module $M \cong M \oplus M$ then if $S=\operatorname{Hom}_R(M,M)$ we have $S \cong S \oplus S$ 3 What is the center of $End_A(S)$? 2 Difference between permutation and combination 2 Let $M$ be a a left module over the algebra of formal power series, $K=\mathbb{C}[[h]]$

### Tags (244)

 18 abstract-algebra × 59 5 pi 8 ring-theory × 5 5 soft-question 7 modules × 6 5 big-list 5 geometry × 7 4 group-theory × 15 5 proof-verification × 7 4 permutations × 5

### Bookmarks (469)

 150 Is there another simpler method to solve this elementary school math problem? 100 Is this continuous analogue to the AM–GM inequality true? 67 Why do engineers use derivatives in discontinuous functions? Is it correct? 62 Is it possible to find an infinite set of points in the plane where the distance between any pair is rational? 61 Is there any geometrical intuition for the factorials in Taylor expansions?