物理量之间存在某种因果关系,这种因果关系的变化率就是对这一物理量进行求导,表现为图线的斜率。综合物体实际情景,因果关系,根据物理规律列出关系式,直接从导数的表达式,判断物理量之间的因果关系,事半功倍。 There is a causal relationship between the physical quantities, the causal relationship between the rate of change is to guide the physical quantities, the performance of the slope of the graph line. According to the actual situation of the object and the causal relationship, the relations are listed according to the laws of physics, and the causal relationship between the physical quantities can be judged directly from the expressions of the derivatives so as to be more effective.