課程名稱︰實分析一
課程性質︰數學研究所必選修、應用數學科學研究所必選修、數學系選修
課程教師︰劉豐哲
開課學院:理學院
開課系所︰數學系
考試日期︰2014年01月
考試時限:110分鐘
試題 :
Real Analysis I (Fall 2013)
Final Examination
1. (20%) A family {f_α} of integrable function on a measure space (Ω,Σ,μ)
is called uniformly integrable if for any ε > 0, there is δ > 0 such that
if A is contained by Σ with μ(A) ≦ δ, then ∫|f_α|dμ≦ε for all α.
A
Show that if {f_n} is uniformly integrable sequence of functions on Ω which
converges a.e. to an integrable function f on Ω, then
lim ∫|f_n - f|dμ = 0.
n->∞
n
2. Let ω≧0 be integrable on R and let μ be a premeasure defined for open
sets G in R^n by n
μ(G) = ∫ωdλ
n G
Denote by μ* the measure on R constructed from μ by Method I.
(a) (6%) Show that μ*(S) = inf μ(G) where infimum is taken over all open
sets G containing S.
(b) (7%) Show that μ* is a Caratheodory measure and
n
μ*(B) = ∫ωdλ
B
for Borel sets B. μ* n
(c) (7%) Show that L^n is contained by Σ and μ*(A) = ∫ωdλ if A
n A
belongs to L .
3. (20%) Define a function f on (0,∞) by
∞ e^(-xt^2)
f(x) = ∫