1. matching method: an analytical expression is matched to the sum of positive integer powers of one or more polynomials by constant deformation method.

2. Factorization: Factorization is to transform a polynomial into the product of several algebraic expressions.

3. method of substitution: The so-called method of substitution is to replace a part of the original formula with a new argument in a more complicated mathematical formula, thus simplifying it and making the problem easy to solve.

4. Discriminant method and Vieta theorem: discriminant △=b2-4ac of the root of unary quadratic equation ax2+bx+c=0(a, B, C belongs to R, a≠0). Vieta's theorem not only knows one root of a quadratic equation, but also finds another root. Knowing the sum and product of two numbers, and finding these two numbers, we can also find the symmetric function of the root.

Know the reason why children can't learn math well:

1, don't let children learn passively. There are still many students who want to play around in junior high school after they go to high school. This is following the teacher's thinking. I don't have any derivatives, I didn't have a learning method before, and I won't look for them after class. Practice exercises and wait for the class, and the teacher will not write the content of the class before. You just want to take notes in class, and learning without ideas is invalid.

2. When the teacher is in class, he just expresses this knowledge clearly and analyzes the key points and difficulties. However, there are still many students who are not attentive in class. I don't know many pharmacies, but I remember a lot. I don't understand many questions myself, and I won't summarize them after class. Just do your homework quickly. Doing homework only reminds them that they don't understand concepts and rules. Doing the problem can only be accidental.