1. matching method: the function with the shape is, and the maximum value of the function is determined according to the value of the extreme point or boundary point of the quadratic function.
2. Discriminant method: a fractional function in the form of, which is transformed into a quadratic equation about x with coefficient y ... Because ∴≥0, finding the maximum value of y is easy to generate root growth, so it is necessary to check whether the corresponding value of x has a solution when finding the maximum value.
3. Using the monotonicity of the function: first define the domain and monotonicity of the function, and then find the maximum value.
4. When using mean inequality, shape function sum ≥≤, pay attention to the application conditions of positive and definite. , that is, whether A and B are positive numbers and fixed values, and whether the equal sign of A = B holds.
5. Substitution method: a function in the form of, so that x can be reversed, and then the function about t can be obtained by substituting into the above formula. Pay attention to the range of the domain of t, and then find the maximum value of the function about t ... and the triangle method of substitution and the parameter method of substitution.