Consider the statement: "Let r, y e Z. If ry is even, then r is even...
Questions: 1. Let P be the statement: "For all sets A, B and C. if AUB CAUC then B - ACC." (a) Is P true? Prove your answer. (b) Write out the converse of P. Is the converse of P true? Prove your answer. (c) Write out the contrapositive of P. Is the contrapositive of true? Explain.
11. (8 marks) Let F(x, y, z) = x'yz, where r, y,z E R and y, z 2 0. Execute the following steps to prove that F(z,y,2) < (y 11(a) Assume each of r, y, z is non-zero and so ryz= s, where s> 0. Prove that 3 F(e.y.) (y)( su, y su, z sw and refer back to Question (Hint: Set 10.) 11(b) Show that if r 0 or y0 or z 0, then F(z, y, z) ( 11(c)...
2. (a) Consider the statement ducks quack If all chickens lay eggs then some Write down in words the (i) conversE (ii) contrapositive (b) Now consider the statement For every tree on the Barr Smith Lawns there is a leaf tree that did not fall off last autumn on that Write down (in words) the negation of this statement 2. (a) Consider the statement ducks quack If all chickens lay eggs then some Write down in words the (i) conversE...
2. Consider the relation E on Z defined by E n, m) n+ m is even} equivalence relation (a) Prove that E is an (b) Let n E Z. Find [n]. equivalence relation in [N, the equivalence class of 3. We defined a relation on sets A B. Prove that this relation is an (In this view, countable sets the natural numbers under this equivalence relation). exactly those that are are 2. Consider the relation E on Z defined by...
3. Let a, b, c E Z such that ca and (a,b) = 1. Show that (c, b) = 1. 4. Suppose a, b, c, d, e E Z such that e (a - b) and e| (c,d). Show that e (ad — bc). 5. Fix a, b E Z. Consider the statements P: (a, b) = 1, and Q: there exists x, y E Z so that ax + by = 1. Bézout’s lemma states that: if P, then...
Let x,y,z e Z. Prove that if x+y= 2, then at least one of , y, and z must be even.
Consider the statement: If the equation is correct it has a positive solution. (a) For each of the statements below, decide on its relationship to the statement above: • The equation is not correct if it has a negative solution. CONVERSE / INVERSE / CONTRAPOSITIVE / NONE OF THESE • The equation has a positive solution only if it is correct. CONVERSE / INVERSE / CONTRAPOSITIVE / NONE OF THESE • If the equation is incorrect it has no positive...
Let z=5 where x, y, z E R. Prove that z? +z2+z?>
1. Consider the following claim. Claim: For two integers a and b, if a + b is odd then a is odd or b is odd. (a) If we consider the claim as the implication P =⇒ Q, which statement is P and which is Q? (b) Write the negations ¬P and ¬Q. (c) (1 point) Write the contrapositive of the claim. (d) Prove the contrapositive of the claim. 2. Use contraposition (proof by contrapositive )to prove the following claim....
mophisn Define an equivalence relation on Rbyy Z and let /Z be the resulting quoi ant rane. Carefully construct a continuous bijection from R/Z. to the circle S(,y) E R+ 1) and prove that it is a homeomorphism. mophisn Define an equivalence relation on Rbyy Z and let /Z be the resulting quoi ant rane. Carefully construct a continuous bijection from R/Z. to the circle S(,y) E R+ 1) and prove that it is a homeomorphism.