Take the exam. The fifth section (variable substitution) is also one of the more important test sites in advanced mathematics 1. The multiple integral test sites of Advanced Mathematics I mainly include the following aspects:

The concepts and properties of 1 and double integral;

2. The concept and properties of triple integral;

3. Variable substitution of multiple integrals;

4. Calculation methods of multiple integrals such as polar coordinates, rectangular coordinates and cylindrical coordinates;

5. The application of multiple integrals, such as calculating the mass and centroid of an object.