In: Advanced Math
Integral
Let f:[a,b]→R and g:[a,b]→R be two bounded functions. Suppose f≤g on [a,b]. Use the information to prove thatL(f)≤L(g)andU(f)≤U(g).
Information:
g : [0, 1] —> R be defined by if x=0, g(x)=1; if x=m/n (m and n are positive integer with no common factor), g(x)=1/n; if x doesn't belong to rational number, g(x)=0
g is discontinuous at every rational number in[0,1].
g is Riemann integrable on [0,1] based on the fact that Suppose h:[a,b]→R is continuous everywhere except at a countable number of points in [a,b]. Then h is Riemann integrable on[a,b].
f : [0,1]→R defined by (f(x) =0 if x = 0) and (f(x)=1 if 0 < x≤1)
f is integrable on [0,1]