Direct integration: a method of integrating by using the linear nature of integration and the integral formula.
Substitution integration method: the first substitution integration method (also called integration method) and the second substitution integration method.
The first alternative integration method is to introduce intermediate variables, which need to be replaced after the product; The laws of rounding and differentiation do not introduce intermediate variables;
The second alternative integration method is to introduce a new independent variable and take the original integral variable as the intermediate variable. After the product comes out, it needs to be replaced in turn.
Partial integration: the method of transforming the original integral into another integral by using the partial integral formula. Choose v' has a priority:
① Exponential function and trigonometric function; ② Power function, polynomial; ③ Logarithmic function and inverse trigonometric function
Other integration methods only use some deformation techniques, including rational function integration, rational trigonometric function integration, simple irrational function integration, etc., which are mainly three integration methods.