definition 
  A function is increasing ,  will also increase The quantity , then we are called  than   to function   The average change rate of the increment is . 
  Formula 
  Note: High school mathematics textbook mentioned, displacement  The derivative of time  is speed, then according to physics formula , in this formula (constant function, primary function, secondary function), the average change rate formula can also be written  ()  Different in  in  equal to  and   ), / p>  1 constant function: For general , first calculate the original formula, ; according to another way, , The two results are equal and established. 
  2 function: For general , first calculate the original formula, ; according to another way,  , The two results are equal and established. 
  3 Quadratic function: For general , first calculate, ; , The two-type results are equal, and it is founded. 
  Application 
   Observing the rate of change of stocks  
  We can use the average change rate knowledge, ask a stock in some The average change rate of the time period is thus understanding the trend of stocks and the future trend. 
   To make a lottery  
 
 for the learning derivative is a very important knowledge point in the calculus. The derivative can be understood as the limit of the average change rate when  is . You see, the derivative is actually the limit of the average change in incrementation to 0, is we first learn to learn average change rate? 
 
 
                         
                        
                            This article is from the network, does not represent the position of this station. Please indicate the origin of reprint