For example, it is proved that inequality can be transformed into a function to find monotonicity.

2. Combination of numbers and shapes

Such as that combination of algebra and geometry.

3. Classified discussion

If we want to solve the inequality | a- 1 | < 0, we need to discuss the value of a.

4. Holistic thinking

Such as whole substitution, superposition and multiplication.

Change your mind

Through deductive induction, unknown, unfamiliar and complex problems are turned into known, familiar and simple problems.

6. Analogical thinking

If a new concept emerges

7. Turn to thinking (turn the unknown into the known, the complex into the simple, and the difficult into the easy)

For example, fractional equations are transformed into integral equations, algebraic problems are transformed into geometric problems, and quadrilateral problems are transformed into triangular problems. The methods to realize this transformation are: undetermined coefficient method, collocation method and whole substitution method.