

44. Let f be integrable over Rande > 0. Establish the following three approximation properties. (i)...
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...
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...
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 4: Let f: [0, 1] → R be an integrable function that is continuous at 0. Prove that lim f(") dx = f(0). n+Jo [ Hint: there are several approaches. It might help to first show that for a fixed 0 <b< 1, we have limn700 Sº f(x) dx = b. f(0). ]
Exercise 27.1 Are the following functionals distributions? (a) T(p) Ip(0) (b) T(p)= а, а ЕС. Σ φ(n) (0). (c) T(p) n=0 27.2 The space (IR) of test funct i. One is led naturally to require that test functions he and have bounded support. The space of nitely 9 (R) or simply 9 (recall Definition 15.1.7), est functions y differentiable is denoted by of these functions vanishes outside a bounded interval (which depends on e). (İİ) ф is infinitely differentiable in...
B2. (a) Let I denote the interval 0,1 and let C denote the space of continuous functions I-R. Define dsup(f,g)-sup |f(t)-g(t) and di(f.g)f (t)- g(t)ldt (f,g E C) tEI (i) Prove that dsup is a metric on C (ii) Prove that di is a metric on C. (You may use any standard properties of continuous functions and integrals, provided you make your reasoning clear.) 6 i) Let 1 denote the constant function on I with value 1. Give an explicit...
19.2. Let f : [a,b] → R be integrable. Show that rb 72 (r)dz, un 0O i=1 where a, b > 0 and h (b/a)1/n. In particular, calculate J-3r2dr by consid- ering a partition P which divides the interval [2, 3] into n parts in geometric progression at the points 2, 2h, 2h2,2h3,... ,2h"-1,2h" -3
19.2. Let f : [a,b] → R be integrable. Show that rb 72 (r)dz, un 0O i=1 where a, b > 0 and h (b/a)1/n....
Consider the finite difference matrix operator for the 1D model problem u(/d2- f(x) on domain [0, 1] with boundary conditions u(0) = 0 and u(1) = 0, given by [-2 1 1-2 1 E RnXn h2 1 -2 1 This matrix can be considered a discrete version of the continuous operator d/da2 that acts upon a function(r). (a) Show that the n eigenvectors of A are given by the vectors ) (p-1,... , n) with components and with eigenvalues h2...
Please answer it step by step and Question 2. uniformly
converge is defined by *f=0* clear handwritten,
please, also, beware that for the x you have 2 conditions , such as
x>n and 0<=x<=n
1- For all n > 1 define fn: [0, 1] → R as follows: (i if n!x is an integer 10 otherwise Prove that fn + f pointwise where f:[0,1] → R is defined by ſo if x is irrational f(x) = 3 11 if x...
Problem 11.11
I have included a picture of the question (and the referenced
problem 11.5), followed by definitions and theorems so you're able
to use this books particular language. The information I include
ranges from basic definitions to the fundamental theorems of
calculus.
Problem 11.11. Show, if f : [0,1] → R is bounded and the lower integral of f is positive, then there is an open interval on which f > 0. (Compare with problems 11.5 above and Problem...