Easy to do PowerPoint lesson demo sine Wave

Use PowerPoint to make courseware, because it is easy to learn and easy to make easy to become the teacher's preferred tool. What we're going to talk about today is a demonstration of the sine wave in PowerPoint.

The image of sinusoidal function is an important part of high school mathematics. But for many students, the content of this class is too abstract to be understood. Therefore, the mathematics teacher chooses to use the courseware to demonstrate the sine wave to better complete the teaching task. So how do you make a demo of sine wave in PowerPoint?

I. GENERAL presentation

If the courseware is just a simple demonstration of sine wave image, there is no interactive requirements, and you are using Offcie XP or Version 2003, then the problem becomes very simple.

Click the Oval button on the Drawing toolbar and draw a small sphere in the slide editing window (used to indicate the moving point). Select the Orb, right-click, and select Custom Animation in the pop-up right-click menu to open the Custom Animation task pane. In this task pane, click the Add effect → action path → sine wave command, as shown in Figure 1.

Then you'll see that the orb in the edit window will move along a sine wave path. When it stops moving, you can see a sine wave appear. Select to adjust its size or rotate using the control handle. As shown in Figure 2.

However, do not be happy before the show, you can only see the ball along the path movement, the path itself (sine wave) is not displayed. Want to show the sine wave? Then we have to move.

Click menu command "view → Zoom ...", select "100%" in the Open Zoom dialog box, press "Print screen" button, copy and paste it into the drawing board, make the appropriate edits, keep the path section only, save.

Then click the menu command "Insert → picture → from file ...", insert the path map into the editing window, and carefully adjust the position of the picture so that the path in the picture is exactly the same as the path in the edit window (you can press the CTRL key and coordinate the arrow keys on the keypad to move pixels by pixel). Don't forget to adjust the "stacking order" of the ball. Ah, on the safe side, put it to the top of the layer (the adjustment method is right click the ball, in the right menu click "stacking order → put the top level" command). OK, now, you can show it and feel the effect.

We can adjust the speed of the small ball movement to get a better demo effect: Double-click the sine Wave path, open 3 of the "Sine wave" dialog box. Click on the Timing tab, see?

By default it is two seconds to complete the animation, of course, it will feel faster. Enter the time (in seconds) you want in the speed input box, and then click the OK button.

Second, custom sine function of the image

Although the above method is simple and quick to make, the inconvenience is obvious. That is, it can not accurately demonstrate the function image according to the actual needs of our class. In teaching practice, we often draw accurate y=asin (ωx+φ) images based on different A, ω, φ values. Obviously, the above method is impossible to complete. However, in PowerPoint, the use of VBA can still make our requirements meet.

First click on the menu command "view → toolbar → Control toolbox" to open the Control Toolbox toolbar. Click the text Box tool in the toolbar and drag and drop three text entry boxes in the edit window. We will use these three text boxes to receive the values of a, ω, φ, respectively, of the slide show, and use these three values to draw a function y=asin (ωx+φ) image.

Click the command button tool in the Control Toolbox to drag and drop a button in the edit window. Select it, right-click, and select Properties from the pop-up shortcut menu to open the Properties dialog box. As shown in Figure 4. Change the contents on the right side of "Caption" to "paint" and Change "False" to "True" to the right of "AutoSize". The other can take the default form. Click on the "OK" button.

Still select the Paint command button, right-click, and select "View Code" from the pop-up shortcut menu to open the VBA Code editing window. Enter the following code in the window:

Private Sub CommandButton1_Click()
A = Val(TextBox1.Text) * 20
B = Val(TextBox2.Text)
C = Val(TextBox3.Text) * 3.14 * 20 / 180
SlideShowWindows(1).View.DrawLine 70, 200, 600, 200
SlideShowWindows(1).View.DrawLine 100, 60, 100, 400
Do While Count < 450
x1 = Count + 100
y1 = -A * Sin((B * Count + C) / 20) + 200
Count = Count + 1
x2 = Count + 100
y2 = -A * Sin((B * Count + C) / 20) + 200
SlideShowWindows(1).View.DrawLine x1, y1, x1, y2
Loop
End Sub

Show, enter three variable values, click the "Paint" button to see how the effect? As shown in Figure 5 (the Last text box should enter the angle of φ).

You can enter data multiple times and draw multiple function images for easy observation. To clear these images, you can use the above method to make a button, the text on the button is set to "clear image", edit the code as:

Private Sub CommandButton3_Click()
SlideShowWindows(1).View.EraseDrawing
End Sub

Want a coordinate system? Oh, if you are not afraid of trouble, of course. Make the third button, the button text is "Draw coordinate system", edit code is:

Rivate Sub Commandbutton3_click ()
H = 100
K = 200
Length = 15.7
Number = 500
Dim XX
XX = 1
Do While XX < number
If xx Mod 4 = 0 Then
SlideShowWindows (1). View.drawline H + xx * length, k-7, H + xx * length, k
SlideShowWindows (1). View.drawline h-xx * length, k-7, h-xx * length, K
SlideShowWindows (1). View.drawline h, k-xx * (length + 4.3), H + 7, K-xx * (length + 4.3)
SlideShowWindows (1). View.drawline h, k + xx * (length + 4.3), H + 7, K + xx * (length + 4.3)
Else
SlideShowWindows (1). View.drawline H + xx * length, k-3, H + xx * length, k
SlideShowWindows (1). View.drawline h-xx * length, k-3, h-xx * length, K
SlideShowWindows (1). View.drawline h, k-xx * (length + 4.3), H + 3, K-xx * (length + 4.3)
SlideShowWindows (1). View.drawline h, k + xx * (length + 4.3), H + 3, K + xx * (length + 4.3)
End If
xx = xx + 1
Loop
SlideShowWindows (1). View.drawline h, K, H + xx * Length, K
SlideShowWindows (1). View.drawline h-xx * Length, K, H, K
SlideShowWindows (1). View.drawline h, K, H, K-xx * Length
SlideShowWindows (1). View.drawline h, K, H, K + xx * Length
End Sub

OK, try again. As shown in Figure 6. Oh, enough "professional" it? Use it to demonstrate the sine wave, right?