Honey, the formulas in the class are all targeted. Usually, when a teacher finishes a formula, he will let you answer the questions with this formula, without considering other formulas. There is more than one formula for homework. You may have learned many formulas, so you should choose a suitable one to use.

The reasons for not doing it after class are: 1. You don't understand the meaning of each formula, and you don't grasp the scope of application of the formula; 2. I have mastered it in class, but I haven't consolidated it in time after class, which leads to forgetting formulas or confusing multiple formulas.

Suggestion: 1. We should fully understand the formula in each lesson and understand what the formula is used to solve; 2. Consolidate the understanding and application of the formula with exercises; 3. Focus on reviewing confusing formulas.

I wish you good grades.