Methods from Fubini and iterated integrals
All methods from Fubini and iterated integrals.
Choose an order of integration
To compute a double integral over a rectangle:
- inspect the integrand for a direct antiderivative in or ;
- write the corresponding inner integral first;
- evaluate the inner integral while treating the other variable as constant;
- evaluate the remaining one-variable integral;
- use the other order as a check when it is comparably simple.
Under Fubini's hypotheses the two orders give the same value, but they need not be equally convenient.