Yes This double integral calculation is generally divided into two steps, one is simplification and the other is calculation. Many big topics are still very simple. Postgraduate entrance examination mathematics double integral has steps. Postgraduate entrance examination generally refers to the national unified postgraduate entrance examination, which refers to the general name of the relevant examinations organized by the education authorities and enrollment institutions for the selection of graduate students, and consists of the initial examination and re-examination organized by the national examination authorities and enrollment units.