Reverse order integration
In some situations it may be impossible to solve a multiple integral in one order (at least with finite terms), but possible in another. For example, in the double integral
the inner integral cannot be solved1. However, in reverse order, it is perfectly solvable.
Finding integral bounds
To reverse the order of an integral it is necessary to “reverse engineer” the integral bounds. Multiple coloured pens is recommended.

Practice problems
- 2016. Calculus, p. 1049 (§15.2 exercises 45–56)
- 2023. Advanced Mathematical Methods, p. 27 (§1 problems 3–4)
Footnotes
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2023. Advanced Mathematical Methods, p. 6 ↩