Question

Prove the following statements by contradiction a) If x∈Z is divisible by both even and odd...

Prove the following statements by contradiction

a) If x∈Z is divisible by both even and odd integer, then x is even.

b) If A and B are disjoint sets, then A∪B = AΔB.

c) Let R be a relation on a set A. If R = R−1, then R is symmetric.

Homework Answers

Know the answer?
Your Answer:

Post as a guest

Your Name:

What's your source?

Earn Coins

Coins can be redeemed for fabulous gifts.

Not the answer you're looking for?
Ask your own homework help question
Similar Questions
Definition of Even: An integer n ∈ Z is even if there exists an integer q...
Definition of Even: An integer n ∈ Z is even if there exists an integer q ∈ Z such that n = 2q. Definition of Odd: An integer n ∈ Z is odd if there exists an integer q ∈ Z such that n = 2q + 1. Use these definitions to prove the following: Prove that zero is not odd. (Proof by contradiction)
Let x, y ∈Z. Prove that (x+1)y^2 is even if and only if x is odd...
Let x, y ∈Z. Prove that (x+1)y^2 is even if and only if x is odd and y is even.
3.a) Let n be an integer. Prove that if n is odd, then (n^2) is also...
3.a) Let n be an integer. Prove that if n is odd, then (n^2) is also odd. 3.b) Let x and y be integers. Prove that if x is even and y is divisible by 3, then the product xy is divisible by 6. 3.c) Let a and b be real numbers. Prove that if 0 < b < a, then (a^2) − ab > 0.
5. Prove or disprove the following statements: (a) Let R be a relation on the set...
5. Prove or disprove the following statements: (a) Let R be a relation on the set Z of integers such that xRy if and only if xy ≥ 1. Then, R is irreflexive. (b) Let R be a relation on the set Z of integers such that xRy if and only if x = y + 1 or x = y − 1. Then, R is irreflexive. (c) Let R and S be reflexive relations on a set A. Then,...
Let n be an integer, with n ≥ 2. Prove by contradiction that if n is...
Let n be an integer, with n ≥ 2. Prove by contradiction that if n is not a prime number, then n is divisible by an integer x with 1 < x ≤√n. [Note: An integer m is divisible by another integer n if there exists a third integer k such that m = nk. This is just a formal way of saying that m is divisible by n if m n is an integer.]
Use the method of direct proof to prove the following statements. 26. Every odd integer is...
Use the method of direct proof to prove the following statements. 26. Every odd integer is a difference of two squares. (Example 7 = 4 2 −3 2 , etc.) 20. If a is an integer and a^ 2 | a, then a ∈ { −1,0,1 } 5. Suppose x, y ∈ Z. If x is even, then x y is even.
Let F = {A ⊆ Z : |A| < ∞} be the set of all finite...
Let F = {A ⊆ Z : |A| < ∞} be the set of all finite sets of integers. Let R be the relation on F defined by A R B if and only if |A| = |B|. (a) Prove or disprove: R is reflexive. (b) Prove or disprove: R is irreflexive. (c) Prove or disprove: R is symmetric. (d) Prove or disprove: R is antisymmetric. (e) Prove or disprove: R is transitive. (f) Is R an equivalence relation? Is...
1)Let ? be an integer. Prove that ?^2 is even if and only if ? is...
1)Let ? be an integer. Prove that ?^2 is even if and only if ? is even. (hint: to prove that ?⇔? is true, you may instead prove ?: ?⇒? and ?: ? ⇒ ? are true.) 2) Determine the truth value for each of the following statements where x and y are integers. State why it is true or false. ∃x ∀y x+y is odd.
Consider the following relation on the set Z: xRy ? x2 + y is even. For...
Consider the following relation on the set Z: xRy ? x2 + y is even. For each question below, if your answer is "yes", then prove it, if your answer is "no", then show a counterexample. (i) Is R reflexive? (ii) Is R symmetric? (iii) Is R antisymmetric? (iv) Is R transitive? (v) Is R an equivalence relation? If it is, then describe the equivalence classes of R. How many equivalence classes are there?
Prove the following: Let n∈Z. Then n2 is odd if and only if n is odd.
Prove the following: Let n∈Z. Then n2 is odd if and only if n is odd.