Recall, a rule assigning elements of a set A to a set B is said to be well-defined if the assignment of elements in A to those of B is unique. Furthermore, such a rule is said to be a function when it is well-defined. Consider the rule f : Q → Z where f m n = m − n for any q = m n ∈ Q. Explain why this rule is not a function.
Note that the m/n representation of a specific rational number is not unique. That is,
and so on.
Thus in this case and again
.
Hence this rule is not well-defined. Hence f is not a function.
Recall, a rule assigning elements of a set A to a set B is said to...
(2) For an integer n, let Z/nZ denote the set of equivalence classes [k) tez: k -é is divisible by n (a) Prove that the set Z/nZ has n elements. (b) Find a minimal set of representatives for these n elements. (c) Prove that the operation gives a well-defined addition on Z/nZ Hint: The operution should not depend on the choice of coset representatives Verify that this gives Z/n2 the structure of an ahelian group. Be sure to verify all...
Let A be a set with m elements and B be a set with n elements in it. -When is it possible to have a k-to-1 function f such that f : A → B? -Count the number of k-to-1 functions f such that f : A → B
6. Consider the function Q(z) = Az[+ B2:1x2+ Cr where A, B, and C are numbers not all zero, = 0 and the level sets of the associated quadratic form; and recall the well-known classification rule for conic sections by the discriminant (B2 -4AC): if B2 - 4AC < 0, then the conic is an ellipse; if B2-4AC = 0, then the conic is an parabola; and if B2-4AC > 0, then the conic is a hyperbola. (a) Complete the...
Let f be a function defined as follows: 1 ?:Q−{0}→R, ?(?)=1− . ? Determine the set ?(?) ?h??? ????h????????? Q ??????? ?={?: ?=?, 1 Write down the set ?(?) by listing the elements as well as in the descriptive form ?∈Z−{0}}
problem 23 please :) and here is Q.21 Problem 23. Recall from Problem 21 the equivalence relation ~ on the set of rational Cauchy sequences C. Define 〈z) E C to be eventually positive if there is an M є N such that xn > 0 for all Prove that eventually positive is a well defined notion on c/ (z〉 ~ 〈y), then 〈y〉 İs eventually positive. ie. if 〈z) is eventually positive and Problem 21. Let C be the...
Let A be a set with m elements and B a set of n elements, where m, n are positive integers. Find the number of one-to-one functions from A to B.
Let U be a set, and let A CU. Recall the indicator function XA: U + Z, defined by XA(x) = ſi, rEA 0, A. Now, let A, B CU and consider the symmetric difference of A and B defined by A AB= (A - B)U(B - A). (a) Show that AAB CU, and compute Ø A A. (b) Prove that Ve EU, XAAB(C) = XA(2) + XB(2), where addition is taken modulo 2 (so that 1+1 = 0).
1. (9pts) Suppose A is a set with m elements and B is a set with n elements. a. How many relations are there from A to B? Explain b. How many functions are there from A to B? Explain C. How many relations from A to itself are reflexive? Explain
Recall that if A is an m times n matrix and B is a p × q matrix, then the product C = AB is defined if and only if n = p. in which case C is an m × q matrix. a. Write a function M-file that takes as input two matrices A and B, and as output produces the product by rows of the two matrices. For instance, if A is 3 times 4 and B is...
Let H-{2m : m ajbe H. (a) Show that R is an equivalence relation. (b) Describe the elements in the equivalence class [3] Z). A relation R is defined on the set Q+ of positive rational numbers by R b if Let H-{2m : m ajbe H. (a) Show that R is an equivalence relation. (b) Describe the elements in the equivalence class [3] Z). A relation R is defined on the set Q+ of positive rational numbers by R...