How to simplify expression
$$\int_a^b f(x)dx+\int_{f(a)}^{f(b)} f^{-1}(x)dx \ ?$$
The answer is $bf(b)-af(a)$ but I am wondering how to get the answer.
How to simplify expression
$$\int_a^b f(x)dx+\int_{f(a)}^{f(b)} f^{-1}(x)dx \ ?$$
The answer is $bf(b)-af(a)$ but I am wondering how to get the answer.