I need help with the following problem. Can anyone help me on this? Thank you in advance.
Let A in Rn be bounded with volume.
Suppose that U is an open subset of Rn such that the closure of A cl(A) is contained in U , and that g:U-->Rn is one-to-one and g^-1 is C1 on g(U) with Jg-1(x) ≠ 0 for all x in g(A).
Prove that if f is integrable on g(A), then f o g is integrable on A.