
SENIOR HIGH MATH LEAGUE April 24, 2001 GROUP IV Emphasis
... Find the exact area of a triangle whose sides are given by 5 cm, 8 cm, and 12 cm. Express your answer in simplest form. ...
... Find the exact area of a triangle whose sides are given by 5 cm, 8 cm, and 12 cm. Express your answer in simplest form. ...
Week 4
... Ok, so we have learned that points in A are good enough to determine continuity of functions, but these points are not necessarily limits of sequences in A. It turns out that there is an alternative characterization of these points. Definition 8.4. Let X be a space and A ✓ X. A point x 2 X is said t ...
... Ok, so we have learned that points in A are good enough to determine continuity of functions, but these points are not necessarily limits of sequences in A. It turns out that there is an alternative characterization of these points. Definition 8.4. Let X be a space and A ✓ X. A point x 2 X is said t ...
4 Choice axioms and Baire category theorem
... property of tame objects is proved using wild objects, it does not bother me. I only want to mark the wild objects by a warning “for internal use only”.2 Mathematics provides models for other sciences. Normally, only tame objects are used in these models.3 A Vitali set is wild. Recall also the Banac ...
... property of tame objects is proved using wild objects, it does not bother me. I only want to mark the wild objects by a warning “for internal use only”.2 Mathematics provides models for other sciences. Normally, only tame objects are used in these models.3 A Vitali set is wild. Recall also the Banac ...
linear representations as modules for the group ring
... A- EndA V bimodule: for associative k-algebras C and D with identity, a C-D bimodule, denoted suggestively by C VD , is a k-module V that is simultaneously a left C-module and a right D-module and satisfies (cv)d = c(vd). Applying the above to the speical case A = k, every left k-module V is natural ...
... A- EndA V bimodule: for associative k-algebras C and D with identity, a C-D bimodule, denoted suggestively by C VD , is a k-module V that is simultaneously a left C-module and a right D-module and satisfies (cv)d = c(vd). Applying the above to the speical case A = k, every left k-module V is natural ...
1. If a polygon has both an inscribed circle and a circumscribed
... 2a2 = b2 1 = (b 1)(b + 1). This implies …rst that b has to be an odd number, and this further implies that a has to be an even number, because (b 1)(b + 1) is a multiple of 4. Let a = 2s and b = 2t + 1. Introducing these in the relation above, we get: 8s2 = 4t(t + 1), or 2s2 = t(t + 1). The product ...
... 2a2 = b2 1 = (b 1)(b + 1). This implies …rst that b has to be an odd number, and this further implies that a has to be an even number, because (b 1)(b + 1) is a multiple of 4. Let a = 2s and b = 2t + 1. Introducing these in the relation above, we get: 8s2 = 4t(t + 1), or 2s2 = t(t + 1). The product ...
JRF IN MATHEMATICS 2011
... Functional analysis and Linear algebra (6) Let y1 , y2 , . . . be a sequence in a Hilbert space. Let Vn be the linear span of {y1 , y2 , . . . , yn }. Assume that kyn+1 k ≤ ky − yn+1 k for each y ∈ Vn for n = 1, 2, 3, . . .. Show that hyi , yj i = 0 for i 6= j. (7) Let E and F be real or complex nor ...
... Functional analysis and Linear algebra (6) Let y1 , y2 , . . . be a sequence in a Hilbert space. Let Vn be the linear span of {y1 , y2 , . . . , yn }. Assume that kyn+1 k ≤ ky − yn+1 k for each y ∈ Vn for n = 1, 2, 3, . . .. Show that hyi , yj i = 0 for i 6= j. (7) Let E and F be real or complex nor ...
ON THE APPLICATION OF SYMBOLIC LOGIC TO ALGEBRA1 1
... other characteristic) is complete in Tarski's sense, as defined in his calculus of systems. However, the statement of this fact as a transfer principle is more suggestive from the point of view of a working mathematician. In the proof, considerable use will be made of the results of Steinitz' field ...
... other characteristic) is complete in Tarski's sense, as defined in his calculus of systems. However, the statement of this fact as a transfer principle is more suggestive from the point of view of a working mathematician. In the proof, considerable use will be made of the results of Steinitz' field ...
8. Commutative Banach algebras In this chapter, we analyze
... This is a commutative Banach algebra if we use matrix multiplication and an arbitrary operator norm on A; in fact, A is a (commutative) subalgebra of C2×2 = B(C2 ). Exercise 8.5. Find all complex homomorphisms. Then show that there are T ∈ A, T 6= 0 with φ(T ) = 0 for all φ ∈ ∆. In other words, Tb = ...
... This is a commutative Banach algebra if we use matrix multiplication and an arbitrary operator norm on A; in fact, A is a (commutative) subalgebra of C2×2 = B(C2 ). Exercise 8.5. Find all complex homomorphisms. Then show that there are T ∈ A, T 6= 0 with φ(T ) = 0 for all φ ∈ ∆. In other words, Tb = ...
Sheaves of Groups and Rings
... (ii) For every nonempty open set U and open cover {Vi }i∈I by nonempty open sets Vi together with matching sections si ∈ P (Vi ), then there is a unique amalgamation s ∈ P (V ). Remark 3. Since P (X) is a functor category and Sets is complete and cocomplete, the category P (X) is complete and cocomp ...
... (ii) For every nonempty open set U and open cover {Vi }i∈I by nonempty open sets Vi together with matching sections si ∈ P (Vi ), then there is a unique amalgamation s ∈ P (V ). Remark 3. Since P (X) is a functor category and Sets is complete and cocomplete, the category P (X) is complete and cocomp ...
LIE-ADMISSIBLE ALGEBRAS AND THE VIRASORO
... Let A be an (nonassociative) algebra with multiplication x y over a field F, and denote by A− the algebra with multiplication [x, y] = x y − yx defined on the vector space A. If A− is a Lie algebra, then A is called Lie-admissible. Lie-admissible algebras arise in various topics, including geometry ...
... Let A be an (nonassociative) algebra with multiplication x y over a field F, and denote by A− the algebra with multiplication [x, y] = x y − yx defined on the vector space A. If A− is a Lie algebra, then A is called Lie-admissible. Lie-admissible algebras arise in various topics, including geometry ...
Math 210B. Absolute Galois groups and fundamental groups 1
... 1. Separable field extensions and covering spaces 1.1. Review of covering spaces. Let X be a path-connected topological space, and x0 ∈ X a point. The fundamental group π1 (X, x0 ) classifying homotopy classes of loops in X based at x0 is a key tool in the study of covering spaces q : X 0 → X, at le ...
... 1. Separable field extensions and covering spaces 1.1. Review of covering spaces. Let X be a path-connected topological space, and x0 ∈ X a point. The fundamental group π1 (X, x0 ) classifying homotopy classes of loops in X based at x0 is a key tool in the study of covering spaces q : X 0 → X, at le ...
Homological algebra

Homological algebra is the branch of mathematics that studies homology in a general algebraic setting. It is a relatively young discipline, whose origins can be traced to investigations in combinatorial topology (a precursor to algebraic topology) and abstract algebra (theory of modules and syzygies) at the end of the 19th century, chiefly by Henri Poincaré and David Hilbert. The development of homological algebra was closely intertwined with the emergence of category theory. By and large, homological algebra is the study of homological functors and the intricate algebraic structures that they entail. One quite useful and ubiquitous concept in mathematics is that of chain complexes, which can be studied both through their homology and cohomology. Homological algebra affords the means to extract information contained in these complexes and present it in the form of homological invariants of rings, modules, topological spaces, and other 'tangible' mathematical objects. A powerful tool for doing this is provided by spectral sequences.From its very origins, homological algebra has played an enormous role in algebraic topology. Its sphere of influence has gradually expanded and presently includes commutative algebra, algebraic geometry, algebraic number theory, representation theory, mathematical physics, operator algebras, complex analysis, and the theory of partial differential equations. K-theory is an independent discipline which draws upon methods of homological algebra, as does the noncommutative geometry of Alain Connes.