1, subtraction rule: (f(x)-g(x))'=f'(x)-g'(x).

2. Addition rule: (f(x)+g(x))'=f'(x)+g'(x).

3. Multiplication rule: (f(x)g(x))'=f'(x)g(x)+f(x)g'(x).

4. Division rule: (g (x)/f (x)' = (g' (x) f (x)-f' (x) g (x))/(f (x)) 2.

The methods of learning derivatives are:

1, number-shape combination

To learn derivatives well, we must first understand the meaning of derivatives, draw pictures according to the meaning of the questions, and understand the basic application of derivatives.

2. The concept of overall substitution

Mathematical derivative multiple-choice questions can also get the correct answer by using the idea of whole substitution, or substitute a specific value for derivative operation.

3. Classified discussion

Different types of problems have different solutions. In the face of some special derivative problems, we need to classify and summarize, find out the rules and summarize the methods. Mathematical derivative formula is the basis of learning mathematical derivative well. I know the formula by heart and can use it flexibly. Problems will be solved naturally, and the effect of improving grades will be more obvious.