Winplot Graphing Software
To Start
Winplot starts by opening a very small startup program. Choose 2-dim in the WINDOW pull down menu. This brings you to a two dimensional grid.
Setup the Grid
1. Setting up the axes.
Under the VIEW menu choose VIEW, which opens up
the window shown here. This lets you set up the window
for your axes. If you select set corners (the top bubble)
you can set the left, right values for the x–axis
and the down, up values for the y–axis. This is
very similar to the window settings on a graphing
calculator. After changing any of the values you must
choose apply.
2. Grid Options
Under VIEW choose GRID, which opens up the window
to the right. Here you can format your axes.
Set up your graph:
· Choose arrows to appear on the axes.
· Choose tick marks on the axes
· Under interval, click on scale for both the x and y axis.
· Choose how many decimal places for the scale. Usually, you will want to make this 0.
· Frequency means how frequently do you want the tick marks labeled?
3. Entering Equations to Graph
Choose the Equa menu, and then explicit to enter equations of the form f(x)= . *** Note : f(x)= is the same as y=
A small dialog box will appear. This is where you will enter your function and control how it will appear on the graph.
*** Note: With integral exponents xx is easier than typing x^2.
· Press F1, or choose Equa, Explicit.
· Replace where it says “xsin(x)” with your equation.
· You may choose to edit the pen width to make the line easier to see. Enter ‘2’ in the pen width text box.
· You can also change the colour. Click the ‘color’ button and choose a colour you like. This is particularly useful when you are graphing several functions at once.
· When you click OK, your graph should display.
· Note: You don’t need to enter a multiplication symbol between most terms:
o ex. 2(3x) works as 2*(3*x) and xx means x * x and ABx means A*B*x (different from most programming languages if you are a programmer)
· To limit the domain of x (the lowest to highest values of x):
o Choose lock interval
o Enter the lower and upper values for x.
· To enter equations for circles or ellipses:
o Choose Equa, Implicit
o Enter equation. For example: xx+yy+36=0 Will give you a circle with a radius of 6.
· To enter vertical lines:
o Choose Equa, Implicit
o Enter equation. For example: x=1 with give you a vertical line with a x-intercept of 1.
4. Managing Functions: Inventory
Under Equa choose Inventory to
get the window shown to the right.
This window lets you see the equations
you have graphed. You can edit or delete
equations.
You can
· Hide the graph and bring it back later
· Hide or show the equation on the graph.
· Look up the table of values.
5. Changing Axes Properties
Under the VIEW/AXIS menu you can set the colour of the axes, graphs etc.
You can also set the axes screen thickness, which makes it easier to see especially if you are printing a grid. This will make the axes look thicker in Winplot and will also look better when you paste into a word processor.
6. Pasting to Word Processor:
When you are happy with the graph or blank grid, size the graph using FILE|IMAGE SIZE. (5 x 5 works well.) Sizing the graph works better in Winplot.
Then copy it to the clipboard using FILE|COPY TO CLIPBOARD.
In your word processing file, paste the graph where needed.
After pasting a graph into your word processor you should select the picture of the graph and format it to float in front of text, or to have text wrap tight to the graphic. The method for doing this varies depending on your word processor. In Word, Right Click on the Graphic and choose Format, Picture, then go to the Layout tab. After doing this you should be able to move the pictures where you want them and still be able to add text.
7. Tracing a graph:
· On the graph window, choose the One menu and select Slider (same as the Trace function on Graphing Calculators) to get the dialog box as shown at left.
· In the top combo box, choose the function you want to trace.
· Use the slider to change the x value and see the corresponding y value. You can mark points on the graph for future reference.
8. Finding the Intersection point(s)
· With two graphs you can find intersections using the TWO|Intersections menu. You will get the dialog box at right.
· Choose the two functions you want to use.
· Mark points of intersection on your graph.
9. Finding Zeros of a Function
a. To find the zeros of a function, choose One, Zeros.
10. Zooming Tips
a. Zooming: You can zoom in and out on the graph using the PageUp and PageDown keystrokes.
b. Changing the centre of the graph can be helpful when zooming: The quickest way is to right-click on where you would like the center to be.
Investigating Transformations of Quadratics
y = a (x – h)2 + k
Part 1 : Investigating what “a” does.
1. First start with the graph y=x2, and make it a thickness of 3 and the colour red.
2. Change the window size from -15 to 15 on both the x and y axis
3. Graph the following in the same window
a. y=2x2
b. y=5x2
c. y=0.5x2
d. y=0.1x2
e. y=-1x2
f. y=-0.1x2
4. Copy and paste the window into a word document
5. Type a conclusion under the graphs that explains what “a” does to the graph.
Part 2 : Investigating “k”
1. First start with the graph y=x2, and make it a thickness of 3 and the colour red.
2. Make sure the window size from -15 to 15 on both the x and y axis
3. Graph the following in the same window
a. y=x2 - 2
b. y=x2 + 5
c. y=-x2 - 5
4. Copy and paste the window into a word document
5. Type a conclusion under the graphs that explains what “k” does to the graph.
Part 3 : Investigating “h”
1. First start with the graph y=x2, and make it a thickness of 3 and the colour red.
2. Make sure the window size from -15 to 15 on both the x and y axis
3. Graph the following in the same window
a. y=(x – 3)2
b. y=(x + 7)2
c. y=-(x + 2)2
4. Copy and paste the window into a word document
5. Type a conclusion under the graphs that explains what “h” does to the graph.
*** Everything does NOT have to be word processed. You can add it with pencil after printing it out ***
Part 4: Putting it all together
1. First start with the graph y=x2, and make it a thickness of 3 and the colour red.
2. Make sure the window size from -15 to 15 on both the x and y axis
3. Graph the following in the same window
a. y=3(x – 5)2 + 4
b. y=-0.2(x + 7)2 - 5
c. y=-5(x-9)^2 + 2
4. Copy and paste the window into a word document
5. Label your graphs and briefly explain how they should look in comparison to the basic parabola y=x2 with regards to the following:
a. vertically stretched or compressed?
b. opening up or down, max or min?
c. vertically translated?
d. horizontally translated?
Part 5 : What should a graph look like?
1. In your word document and without graphing, explain in words what the following graphs should look like (same as above)
a. y = -¾(x+0)2 + 0
b. y = 1(x-1)2 – 1
c. y = 3(x + 10)2 + 10
2. Make sure your name is on your word document. Print it off and add any details with pencil you think should be there (not everything has to be word processed).
3. Hand it in J