Ejercicios de representación de puntos

	EXERCISES - PLOTTING POINTS
	Analysis

1. POINTS OF SYMMETRY

This deals with finding the connection between the coordinates of a point and those of its symmetrical points about each of the axes and the origin.

The boxes sx, sy and s0 activate (1) or deactivate (0) the points symmetrical to the red point.

1.-Look carefully at the x and y-coordinates of the symmetrical points about the X-axis (sx=1)

Try and position the red point in the different quadrants and on the axes. Write a conclusion in your notebook about what you discover.

2.-Repeat the process about the Y-axis (sy=1)

3.-Repeat the process about the origin (s0=1)

4.-In your exercise book draw up a table of the coordinates of the symmetrical points about the X-axis, the Y-axis and the origin for several different points. Examine how the signs change in each case.

2. SYMMETRICAL SHAPES

When a point moves around a shape the symmetrical points form shapes that are symmetrical to the original ones.

To move the red point in straight lines select it with the mouse and then use the arrow keys.

5.-Construct several symmetrical shapes.

Use the Clear button to clear the trace of the points from the diagram.

6.-Construct the following shapes:

3. COORDINATES OF POINTS ON THE SAME HORIZONTAL

This deals with finding the connection between coordinates of points that are on the same horizontal line.

When you move the red point yellow points will indicate its trace. Click on the Clear button to clear this trace.

7.- In your notebook write the coordinates of several points that are on the same horizontal line. What do these coordinates have in common?

You can change the y-coordinate by writing in a new value for y.

8.-What are the coordinates of the horizontal line that goes through the point (1 , -2.6)?

9.-Try different horizontal lines and write a conclusion about what you discover in your exercise book.

4. POINTS WITH IDENTICAL COORDINATES

This deals with finding the connection between points whose x and y-coordinates are the same.

The x and y-coordinates of the red point are always the same.

10.- Look carefully at the position on the axes of the point that have the same x and y-coordinates.

Use the Clear button to clear the yellow trace left by the red button.

11.-What shape do these points make?

12.-What shape do the points with opposite coordinates make?

	Juan Madrigal Muga

	Spanish Ministry of Education. Year 2001

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