Let f : B → A and g : A → B be functions.
(a) What are the domain and co domain of g ◦ f, the composition of g and f?
(b) Prove or disprove the following statement: If g ◦ f is an injection, then f is also an injection.
Let f : B → A and g : A → B be functions. (a) Prove or disprove the following statement: If g ◦ f is an injection, then f is also an injection. (b) Prove or disprove the following statement: If g ◦ f is a surjection, then f is also a surjection.
1. Let f and g be functions with the same domain and codomain (let A be the domain and B be the codomain). Consider the following ordered triple h = (A, B, f LaTeX: \cap ∩ g) (Note: The f and g in the triple refer to the "rules" associated with the functions f and g). Prove that h is a function. Would the same thing be true if, instead of intersection, we had a union? If your answer is...
3. Let f, g : a, b] → R be functions such that f is integrable, g is continuous. and g(x) 〉 0 for all x є a,b]. Since both f, g are bounded, let K 〉 0 be such that |f(x) K and g(x) < K for all x E [a,b (a) Let n > 0 be given. Prove that there is a partition P of [a, b such that for all i 2. (b) Let P be a...
Let f(n) and g(n) be asymptotically positive functions. Prove or disprove each of the following conjectures. f(n) = O(g(n)) implies g(n) = Ω(f(n)) . f(n) = O(g(n)) implies g(n) = O(f(n)). f(n) + g(n) = Θ(min(f(n),g(n))).
3. Let f, g : [a,b] → R be functions such that f is integrable, g is continuous, and g(x) >0 for all r E [a, b] Since both f,g are bounded, let K >0 be such that lf(z)| K and g(x) K for all x E [a3] (a) Let n > 0 be given. Prove that there is a partition P of [a, b such that U (P. f) _ L(P./) < η and Mi(P4)-mi(P4) < η for all...
Problem 10. Let f,g: [a,b] -R be Riemann integrable functions such that f(x) < g(x) for all x E [a,b]. Prove that g(x)
(5) Let (. A, /u) be a measure space. Let f,g : O > R* be a pair functions. Assume that f is measurable and that f = g almost everywhere. (a) Prove that q is measurable on A. Prove that g is integrable (b) Let A E A and assume that f is integrable on A and A (5) Let (. A, /u) be a measure space. Let f,g : O > R* be a pair functions. Assume that...
3. Let f, g : a, bl → R be functions such that f is integrable, g is continuous. and g(x) >0 for al x E [a, b]. Since both f,g are bounded, let K> 0 be such that f(x)| 〈 K and g(x)-K for all x E la,b] (a) Let η 〉 0 be given. Prove that there is a partition P of a,b] such that for all i (b) Let P be a partition as in (a). Prove...
O GRAPHS AND FUNCTIONS Composition of two functions: Domain and range, Two functions g and f are defined in the figure below. Domain of Domain of g Range of g Range of Find the domain and range of the composition fog. Write your answers in set notation. Domain of fºg : 11 Range of fºg : 00 X 5 ?
1. (a) (6 points) Let f : A + B and g:B + C be two functions. Suppose that the composition of functions go f is a bijection. Prove that the function f : A + B must be one-to-one and that the function g:B + C must be onto. (b) (4 points) Give an example of a pair of functions, f and g, such that the composition gof is a bijection, but f is not onto and g is...