Problem 4.4. Let D=Q\{0}, the set of all non-zero rational numbers. For all r, yED, define...
Let r be any rational number and define L = { x in Q: x < r }, the set of rational numbers less than r. Show that L is a Dedekind cut by proving the following properties: A. There exists a rational number x in L and there exists a rational number y not in L. ( This proves L is nonempty and L is not equal to Q) B. If x in L, then there exists z in...
Let (Q, d) be the metric space consisting of the set Q of rational numbers with the standard metric d(x, y) = |x-yl. Show that the Heine Borel theorem fails for (Q,d). In other words, show that (Q, d) has a subset SCQ that is closed and bounded, but not compact
Let (Q, d) be the metric space consisting of the set Q of rational numbers with the standard metric d(x, y) = |x-yl. Show that the Heine Borel theorem fails for (Q,d). In other words, show that (Q, d) has a subset SCQ that is closed and bounded, but not compact
1. Let (Q, d) be the metric space consisting of the set Q of rational numbers with the standard metric d(x, y) = (x – yl. Show that the Heine-Borel theorem fails for (Q, d). In other words, show that (Q, d) has a subset SCQ that is closed and bounded, but not compact (8 points).
2. [14 marks] Rational Numbers The rational numbers, usually denoted Q are the set {n E R 3p, q ZAq&0An= Note that we've relaxed the requirement from class that gcd(p, q) = 1. (a) Prove that the sum of two rational numbers is also a rational number (b) Prove that the product of two rational numbers is also a rational number (c) Suppose f R R and f(x)= x2 +x + 1. Show that Vx e R xe Qf(x) Q...
2. Let X be a continuous random variable. Let R be the set of all real numbers, let Z be the set of all integers, and let Q be the set of all rational numbers. Please calculate (1) P(X ? R), (2) P(X ? Z), and (3) P(X EQ)
Define a class for rational numbers. A rational number is a number that can be represented as the quotient of two integers. For example, 1/2, 3/4, 64/2, and so forth are all rational numbers. (By 1/2 etc we mean the everyday meaning of the fraction, not the integer division this expression would produce in a C++ program). Represent rational numbers as two values of type int, one for the numerator and one for the denominator. Call the class rational Num...
1. (a) Let d be a metric on a non-empty set X. Prove that each of the following are metrics on X: a a + i. d(1)(, y) = kd(x, y), where k >0; [3] ii. dr,y) d(2) (1, y) = [10] 1+ d(,y) The proof of the triangle inequality for d(2) boils down to showing b + > 1fc 1+a 1+b 1+c for all a, b, c > 0 with a +b > c. Proceed as follows to prove...
Let V be R2, the set of all ordered pairs (x, y) of real numbers. Define an operation of "addition" by (u, v) @ (x, y) = (u + x +1, v + y + 1) for all (u, v) and (x, y) in V. Define an operation of "scalar multipli- cation" by a® (x, y) = (ax, ay) for all a E R and (x,y) E V Under the two operations the set V is not a vector space....
1. Let Q be the set of polynomials with rational coefficients. You may assume that this is an abelian group under addition. Consider the function Ql] Q[x] given by p(px)) = p'(x), where we are taking the derivative. Show that is a group homomorphism. Determine the kernel of 2. Let G and H be groups. Show that (G x H)/G is isomorphic to H. Hint: consider defining a surjective homomorphism p : Gx HH with kernel G. Then apply the...