"Location of Coordinates and Graphics" PPT download

Description

"Location of Coordinates and Graphics" PPT download

Part One Content: Learning Objectives:

1. Be able to flexibly establish an appropriate rectangular coordinate system according to the characteristics of graphics and the needs of the problem.

2. Through the process of establishing a plane rectangular coordinate system, understand the idea of ​​combining numbers and shapes, and feel the corresponding relationship between points and coordinates.

Important and difficult points:

Teaching focus:

Optionally establish a rectangular coordinate system and represent the coordinates of points on the graph.

Teaching difficulties:

According to the characteristics of the graphics and the needs of the problem, establish an appropriate coordinate system.

Coordinates and the position of graphics PPT, part 2 content: intensive lecture:

As shown in the picture, Xiaoliang drew a quadrilateral and wanted to tell Xiaoqiang its shape over the phone so that Xiaoqiang could accurately draw the same shape. He wanted everyone to think of a way for him.

Xiao Ming said: "Establish a rectangular coordinate system and tell the coordinates of the four vertices of this quadrilateral to draw the same figure." Do you think Xiao Ming's statement is feasible? Give reasons.

A square with a side length of 4 is known. Establish an appropriate rectangular coordinate system and describe its position through the coordinates of each vertex.

(1) As shown in the figure, (1), (2), and (3) are the rectangular coordinate systems established by three students. Please fill in the coordinates of each vertex of the quadrilateral in the following table.

(2) What are the advantages of each of these three ways of establishing a rectangular coordinate system? Give your reasons.

(3) Can you establish other rectangular coordinate systems?

Note: Different rectangular coordinate systems are established, and the vertex coordinates of the same figure are also different. An appropriate rectangular coordinate system should be established according to the specific situation.

(2) In the coordinate system (1), one vertex of the square is used as the origin of the coordinates, and the straight line where the two sides are located is used as the coordinate axis, so that more points fall on the coordinate axis, making it easier to calculate the coordinates; in the coordinate system ( 2) In (3), the symmetry axis of the square is used as the coordinate axis. In the process of calculating the coordinates, the properties of the symmetric points about the coordinate axis can be used to simplify the process of calculating the coordinates. At the same time, in the coordinate system (3), four The vertices are all on the coordinate axes.

(3) Can you establish other rectangular coordinate systems?

For the same graph, countless coordinate systems can be established based on the origin and coordinate axes.

visible:

(1) The selected coordinate systems are different, and the coordinates of the same point are different;

(2) In order to simplify the calculation and facilitate the proof, the coordinate system needs to be appropriately selected;

(3) "Appropriate" means making full use of the characteristics of graphics: vertical relationships, symmetrical relationships, parallel relationships, midpoints, etc.

Position of coordinates and graphics PPT, part 3: requirements and principles

Requirements and principles for establishing a plane rectangular coordinate system:

Set the origin and draw two axes

Establishing the system is convenient for coordinate calculation.

As shown in the figure, in the isosceles triangle ABC, the base BC=4 and the height AD=6.

(1) Please establish an appropriate rectangular coordinate system in the grid diagram and write the coordinates of points A, B, and C.

(2) Explain the reason why you chose this coordinate system.

(1) Establish a coordinate system as shown in the figure: take BC midpoint D as the origin, BC, AD as the coordinate axes.

Cartesian coordinate system; as can be seen from the figure, the coordinates of point A are (0, 6), B is (-2, 0), C (2, 0), D (0, 0)

(2) The coordinate system is built in this way so that several points all fall on the coordinate system. At the same time, the symmetry of the isosceles triangle is utilized to simplify the calculation of coordinates.

Coordinates and the position of graphics PPT, part 4 content: analysis of typical questions:

1. As shown in the figure, in the Cartesian coordinate system, the length of the hypotenuse OB of the isosceles right triangle OAB is 4 unit lengths.

(1) Write the coordinates of point B.

(2) How else can we establish a rectangular coordinate system to make the coordinates of each vertex simpler?

(1) Analysis: According to the geometric relationship, OA=AB=2, so the coordinates of point B are (2, 2).

(2) As shown in the figure, △ABC is the triangle, AC is the hypotenuse, its midpoint is the origin of the coordinates, AC is the x-axis, and the perpendicular line from point B to AC is the y-axis. The coordinates of each vertex in the coordinate system formed by this Coordinates are simpler.

It can be seen from the geometric relationship: AO=CO=BO=2, so the coordinates of point A are (-2, 0), B (2, 0), and C are (2, 0).

2. In a summer camp activity, the teacher hid an action plan at point C without any markings, and only told everyone that points A and B were trees respectively, with the coordinates (-30, 10), (30 , 10), the coordinates of point C are (20, 20) (unit: m). Please determine the location of point C and find this action plan as soon as possible.

The position of coordinates and graphics PPT, the fifth part: summary:

1. Be able to flexibly establish different rectangular coordinate systems according to the characteristics of graphics and the needs of the problem.

2. Methods to establish an appropriate coordinate system:

(1) Take a known point as the origin and make its coordinates (0, 0)

(2) Take the straight line where a certain line segment of the graph is located as the x-axis or y-axis

(3) Make use of the symmetry of the graph and use its axis of symmetry as the x-axis or y-axis

(4) Use the midpoint of the known line segment as the origin, and the straight line where the line segment lies is the coordinate axis.

Keywords: Free download of Hebei Education Edition mathematics PPT courseware for the second volume of eighth grade, coordinates and the position of graphics PPT download, .PPT format;

For more information about the "Position of Coordinates and Graphics" PPT courseware, please click the "Position of Coordinates and Graphics" ppt tab.

"Coordinates and the Position of Figures" PPT courseware:

The content of the first part of the PPT courseware "Coordinates and Graphics Positions": Learning objectives: 1. Understand the method of determining the position in the actual model, and be able to correctly draw the plane rectangular coordinate system; 2. Be able to establish an appropriate rectangular coordinate system and mathematically solve practical problems ization, and will use rectangular coordinates..

"Coordinates and the Position of Graphics" PPT:

"Coordinates and the Position of Graphics" PPT Part One: Problem Exploration To describe the coordinates of points on a graphic, can different coordinate systems also be established? Think about the contents of the self-study textbook: 1. What are the advantages of each of the two methods given in the textbook? 2. You still have...

File Info

Update Time: 2024-11-20

This template belongs to Mathematics courseware Hebei Education Edition Eighth Grade Mathematics Volume 2 industry PPT template

Preview