1, the distance between two points on the number axis is the absolute value of the coordinate difference corresponding to these two points, that is, the difference between the number on the right and the number on the left MINUS. That is, the distance between two points on the number axis = the number represented by the right point-the number represented by the left point.
2. When a point moves on the number axis, because the right direction of the number axis is positive, the speed of moving to the right is regarded as positive speed, and the speed of moving to the right is regarded as negative speed. In this way, the coordinates of the point after moving can be directly obtained by adding the moving distance of the point on the basis of the starting point. That is, the number represented by point A is A, and the number represented by shifting unit B to the left is A-B..
Matters needing attention in moving point problem:
The key to the problem of moving point is to seek quietness in motion. Read the stem carefully and extract key information from multiple conditions. Mathematical thinking is the idea of classification, sorting out and classifying the extracted key information. The combination of numbers and shapes and the transformation of ideas, and the combination of numbers and shapes of key information make mathematical problems clear at a glance. Combining the above ideas, we can effectively solve the problem of middle school relocation.
To solve the problem of moving point, the key is to grasp the moving point, turn the moving point into a static one, and find the breakpoint (side length, moving point speed, angle and the equivalent relationship of a given graph, etc.) ), establish the required equivalent algebra, solve problems, find unknowns and so on.
Baidu Encyclopedia-Moving Angle