问答题
求证,设f∈L1[a,b],则∫abf(x)dx∫axf(y)dy=
设f∈L1[0,a],g(x)=,则∫0agdm=∫0afdm
求∫0∞(e-ax2-e-bx2)(0<a<b)
求证,设f,g∈M(X),μX<∞,则f(x)+g(y)∈L1(μ×μ)f,g∈L1(μ)