# How to Create Graphs for Economics

by Stephanie Ellen

A variety of computer programs and tools (including hand-held programmable calculators) are available for you to graph a whole host of economics equations. For example, you might want to create a graph for a supply curve, P = 10 + 2Q, where 10=fixed cost, 2=variable cost and Q=quantity. Choose the tool that works for you: three of the most common tools found on university campuses are the TI83 graphing calculator, and the computer programs MatLab and Maple.

### TI83 Graphing Calculator

Press the "Y=" button.

Enter the equation into the first line of the Y-editor (the cursor will automatically land there when you enter the editor). Replace any variable with "X." For example, P= 10 + 2Q is entered as 10 + 2x.

Press the "Graph" key.

### MatLab

Type the following into the program: "t = 0:.5:100;" This graphs your function from 0 to 100 in steps of 0.5.

Press "Enter," and then type: "y = 10+2x;"

Press "Enter," and then type: "plot(x,y)"

Press "Enter." Matlab will generate the graph.

### Maple

Type your function into the entry line, using the plot command: "plot(10+2x),"

Choose an x-axis range to suit your needs. For example, you might want to display a supply curve up to 1,000. Enter: "plot(10+2x, x = 0..1000);"

Press "Enter."

#### Tip

• check If you are learning one of the programs for the first time, stick to simple equations of one variable (like the sample above) until you get used to how your chosen tool handles order of operations.