Question

1. For each statement that is true, give a proof and for each false statement, give...

1. For each statement that is true, give a proof and for each false statement, give a counterexample

    (a) For all natural numbers n, n2 +n + 17 is prime.

    (b) p Þ q and ~ p Þ ~ q are NOT logically equivalent.

    (c) For every real number x ³ 1, x2£ x3.

    (d) No rational number x satisfies x^4+ 1/x -(x+1)^(1/2)=0.

    (e) There do not exist irrational numbers x and y such that logx y is rational

    (f) n^2+3n+7 is odd for all integers n.    

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
1. Give a direct proof that the product of two odd integers is odd. 2. Give...
1. Give a direct proof that the product of two odd integers is odd. 2. Give an indirect proof that if 2n 3 + 3n + 4 is odd, then n is odd. 3. Give a proof by contradiction that if 2n 3 + 3n + 4 is odd, then n is odd. Hint: Your proofs for problems 2 and 3 should be different even though your proving the same theorem. 4. Give a counter example to the proposition: Every...
Ex 2. Prove by contradiction the following claims. In each proof highlight what is the contradiction...
Ex 2. Prove by contradiction the following claims. In each proof highlight what is the contradiction (i.e. identify the proposition Q such that you have Q ∧ (∼Q)). Claim 1: The sum of a rational number and an irrational number is irrational. (Recall that x is said to be a rational number if there exist integers a and b, with b 6= 0 such that x = a b ). Claim 2: There is no smallest rational number strictly greater...
You’re the grader. To each “Proof”, assign one of the following grades: • A (correct), if...
You’re the grader. To each “Proof”, assign one of the following grades: • A (correct), if the claim and proof are correct, even if the proof is not the simplest, or the proof you would have given. • C (partially correct), if the claim is correct and the proof is largely a correct claim, but contains one or two incorrect statements or justications. • F (failure), if the claim is incorrect, the main idea of the proof is incorrect, or...
Write a formal proof to prove the following conjecture to be true or false. If the...
Write a formal proof to prove the following conjecture to be true or false. If the statement is true, write a formal proof of it. If the statement is false, provide a counterexample and a slightly modified statement that is true and write a formal proof of your new statement. Conjecture: There does not exist a pair of integers m and n such that m^2 - 4n = 2.
A natural number p is a prime number provided that the only integers dividing p are...
A natural number p is a prime number provided that the only integers dividing p are 1 and p itself. In fact, for p to be a prime number, it is the same as requiring that “For all integers x and y, if p divides xy, then p divides x or p divides y.” Use this property to show that “If p is a prime number, then √p is an irrational number.” Please write down a formal proof.
For each of the statements below, say what method of proof you should use to prove...
For each of the statements below, say what method of proof you should use to prove them. Then say how the proof starts and how it ends. Pretend bonus points for filling in the middle. a. There are no integers x and y such that x is a prime greater than 5 and x = 6y + 3. b. For all integers n , if n is a multiple of 3, then n can be written as the sum of...
True Or False 1. If nn is odd and the square root of nn is a...
True Or False 1. If nn is odd and the square root of nn is a natural number then the square root of nn is odd. 2. The square of any even integer is even 3. The substraction of 2 rational numbers is rational. 4. If nn is an odd integer, then n2+nn2+n is even. 5. If a divides b and a divides c then a divides bc. 6. For all real numbers a and b, if a^3=b^3 then a=b.
Determine if each of the following statements is true or false. If a statement is true,...
Determine if each of the following statements is true or false. If a statement is true, then write a formal proof of that statement, and if it is false, then provide a counterexample that shows its false. 1) For each integer a there exists an integer n such that a divides (8n +7) and a divides (4n+1), then a divides 5. 2)For each integer n if n is odd, then 8 divides (n4+4n2+11).
Statement: "For all integers n, if n2 is odd then n is odd" (1) prove the...
Statement: "For all integers n, if n2 is odd then n is odd" (1) prove the statement using Proof by Contradiction (2) prove the statement using Proof by Contraposition
For each problem, say if the given statement is True or False. Give a short justification...
For each problem, say if the given statement is True or False. Give a short justification if needed. Let f : R + → R + be a function from the positive real numbers to the positive real numbers, such that f(x) = x for all positive irrational x, and f(x) = 2x for all positive rational x. a) f is surjective (i.e. f is onto). b) f is injective (i.e. f is one-to-one). c) f is a bijection.
ADVERTISEMENT
Need Online Homework Help?

Get Answers For Free
Most questions answered within 1 hours.

Ask a Question
ADVERTISEMENT