
#4
(4) Use the Box-sum criterion to prove that if f is integrable on [a, b] and is also integrable on |b,e, then f is integrable on la, e) and Je fdr- o fdz+ (5) Suppose that (r) 2 0 and is continuous on a, b). Prove that if f - 0, then f(x) = 0 for all x E a,b]. Hint: Assume to the contrary that there is some r E [a, b] where f(x) > 0. What can...
8. Suppose f : la,b] → R is monotone increasing. Prove that f is integrable. Of course you may not use the theorem that monotone functions are integrable!
8. Suppose f : la,b] → R is monotone increasing. Prove that f is integrable. Of course you may not use the theorem that monotone functions are integrable!
31 (a) If fis integrable, prove that fa is integrable. Hint: Given e>0, let h and k be step functions such that h f k and j (k-h) < ε/M, where M is the maximum value of Ik(x) +h(x)]. Then prove that h and k2 are step functions with h' srsk (we may assume that OShSSk since f is integrable if and only if I is-why?), and that I (k2 - h2) <e. Then apply Theorem 3.3. (b) If fand...
|(16) Let (, A, ) be a measure space and let f finite a.e -> R* be integrable. Prove that f is
|(16) Let (, A, ) be a measure space and let f finite a.e -> R* be integrable. Prove that f is
Let {h} be a sequence ofRiemann integrable functions on [a,b], such that for each x, {h(x)) is a decreasing sequence. Suppose n) converges pointwise to a Riemann integrable function f Prove that f(x)dxf(x)dx. lim n00
Let {h} be a sequence ofRiemann integrable functions on [a,b], such that for each x, {h(x)) is a decreasing sequence. Suppose n) converges pointwise to a Riemann integrable function f Prove that f(x)dxf(x)dx. lim n00
Prove that if ? is integrable on [?, ?] and ?(?) ≥ 0 for all ?
in [?, ?], then
[ f(x)dx > 0 7. Prove that if f is integrable on [a, b] and f(x) > 0 for all x in [a, b], then sof(x)dx > 0.
1. f : riemann integrabel in [0,inf). prove that f is lebesgue integrable iff the improper integral converges absolutly.
(c) Let f :la,b- R be an integrable function. Prove that lim . (Your argument should include why faf makes sense for a < x < b.)
(c) Let f :la,b- R be an integrable function. Prove that lim . (Your argument should include why faf makes sense for a
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...
2. f is the function on (0, 1) given below. (a) Is f integrable? Prove your answer. (b) At what values of x is f discontinuous? Give a short proof of this. _s 1 if if x = 1,,,,...I where neN f(3) = 0 otherwise