Let f : Z * Z -> Z be given by
f(a, b) = a + b - ab:
Is f associative?
If your answer is yes, give a proof. If your answer is no, nd a
counterexample.
Let the function f R R be given by 1,)- f 1 z-1 Draw the graph of f versus the values of z. Is f a bijection (i.e., one-to-one and onto)? If yes then give a proof and derive a formula for f. If no then explain why not Let the function f R R be given by 1,)- f 1 z-1 Draw the graph of f versus the values of z. Is f a bijection (i.e., one-to-one and onto)?...
12. Let f be integrable on a closed interval [a, b]. Suppose that there is a real number C such that f(x) 2C for all E a, b (1) Prove that if С > 0, then, is also integrable on [a,b, (6 Marks) (2) If C 0, i, still integrable (assuming f(x) 0 for any x E [aA)? If yes, supply a short proof. If no, give a counterexample. (6 Marks) 12. Let f be integrable on a closed interval...
12. Let f be integrable on a closed interval [a, b]. Suppose that there is a real number C such that f(x) 2C for all E a, b (1) Prove that if C>0, then 7 is also integrable on la,b] (6 Marks) (2) If C 0, i, still integrable (assuming f(x)关0 for any x E [aM)? If yes, supply a short proof. If no, give a counterexample. (6 Marks) 12. Let f be integrable on a closed interval [a, b]....
Let A = ( a, b, c, d ) and let ( A, R ) be a posset where R is a Relation on A defined by: R is reflexive c ≤ d a ≤ c a ≤ b a ≤ d b ≤ d Find H(A) Is (A, R) a lattice? If you answer no, give a counterexample. If you answer yes, give a brief justification as to why (no formal proof needed). Is (A,R) a Boolean algebra? Give...
Proof or give a counterexample for the following statement Let f:[8,18]. Then f(f-1(G))=G for any G⊆ Justify your answer → * We were unable to transcribe this image
Let X be a set with an equivalence relation ∼. Let f : X/ ∼→ Y be a function with domain as the quotient set X/ ∼ and codomain as some set Y . We define a function ˜f, called the lift of f, as follows: ˜f : X → Y, x 7→ f([x]). We define a function Φ : F(X/ ∼, Y ) → F(X, Y ), f 7→ ˜f. (1) Is Φ injective? Give a proof or a...
(Problem continued) 9 (b). Let F:R ([2) R be given by F In(z +1). Find its Tavlor series up to and inchading the degree 2 term (6 marks F give rise to an inner 2 (c). Referring to the function F in part (b) above, for which values of a does the matrix A (4 marks product on R2? Show how you obtained your answer. (Problem continued) 9 (b). Let F:R ([2) R be given by F In(z +1). Find...
Let X, Y, Z be random variables. Prove or disprove the following statements. (That means, you need to either write down a formal proof, or give a counterexample.) (a) If X and Y are (unconditionally) independent, is it true that X and Y are conditionally indepen- dent given Z? (b) If X and Y are conditionally independent given Z, is it true that X and Y are (unconditionally) independent?
Let F be the set of all real-valued functions having as domain the set R of all real numbers. Example 2.7 defined the binary operations +- and oon F. In Exercises 29 through 35, either prove the given statement or give a counterexample. 29. Function addition + on F is associative. 30. Function subtraction - on is commutative
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...