Final Answer:
a = g(y)
b = f(y)
Step-by-step explanation:
To write an equivalent integral with the order of integration reversed, we switch the limits of integration and interchange the roles of f(y) and g(y). The new integral becomes
In the context of double integration, this process is analogous to changing the order of integration for a double integral. If we have, reversing the order of integration results in
This reversal is useful in certain situations, especially when one order of integration simplifies the calculation or when the region of integration is more naturally described in the reversed order."