The definition of derivative is mainly understood in several aspects:
(1) derivative is defined as the limit of the quotient of the increment of the dependent variable and the increment of the independent variable when the increment of the independent variable tends to zero.
(2) In analytic geometry, it is equivalent to the slope of the tangent of a curve.
(3) Applications in physical concepts, such as speed is the derivative of distance to time and acceleration is the derivative of speed to time.
This concept must be understood on the basis of limit. It will be easier to understand if you understand the definition of limit first, but don't worry if you can't understand it for a while. The knowledge in senior high school is superficial, and a lot of knowledge is ignored, giving the results directly. Just remember to paint it. After all, the definition of limit has taken so many mathematicians a long time to sum up, so it is not a shame that they are so easy to understand. _, come on.