Google Sheets can be used to solve and graph quadratic functions.
In this lesson we will learn how to...
- Generate numbered lists
- Enter a formula into a cell
- Reference values in a cell
- Use exponents in an equation
- Multiply values in an equation
- Create a scatter chart to graph the quadratic function
Create a new Google Sheet by clicking the New button in Google Drive and selecting Google Sheets.
Click on the untitled Sheet name and provide a name for the Google Sheet.
The first thing we need to do is create a table for our values. Skip a few cells down column A and click once on Cell A3.
Type X in cell A3 then click on Cell B3 and type Y.
Click once bellow cell A3 so we can begin to provide values for X. We’ll begin with some negative values.
With sheets we don’t have to manually enter all the number values if they follow a pattern. We can use this pattern and Google sheets will create the additional values for us. Enter values for the first three and then select the cells.
Click on the blue square in the lower right corner and drag it down the column.
Drag the selection down several cells and release. There should be several values for X in our table.
To work on the rest of the quadratic formula we need the formula. Let’s type the formula at the top above the table so we can reference it while developing the table and the graph. Click once on cell A1 and enter (y equals x squared minus 5x+3). In the spreadsheet I used the caret (^) symbol. This symbol is used in spreadsheets for exponents.
Click once on cell B4. This is where we will use the formula we wrote above. To begin the formula type =.
The first variable in our equation is “x”. The value for x is in cell A4. Type A4 after the equal sign. The color of A4 is orange to indicate it is a reference cell. The value of the cell appears above the cell reference in the equation.
This value is squared. Type the caret symbol, which is usually above the number 6 on the keyboard, and the number 2.
After the number 2 type the minus sign and the number 5.
5x is the product of 5 and x. The multiplication symbol is the asterisk. This symbol is usually above the number 8. The value for x is in cell A4 so we type the cell reference A4. For the next part of the equation we need to type the asterisk followed by the cell reference.
Type the plus sign followed by the number 3 for the last part of the equation. Press the return key on your keyboard to complete the process.
The Y value is 53. We don’t need to repeat this math formula creation process for each cell manually. Google Sheets can help us create the formula for the rest of the values in our table. Click once on the cell with our formula.
Click and drag on the blue square in the bottom right corner. Make sure the cursor is in the shape of a plus symbol. Drag the box down to the last value for X.
We can use these values to plot the graph for the equation. Click and drag to select cells A4 to B20 or all the cells with values for the graph.
Click on the chart button in the button bar.
Google Sheets will recommend a chart to use based on the selected data. We can choose the recommended chart which appears to be a line graph.
We can choose a different chart by clicking the chart types tab.
This data for our formula works best if we use a Scatter chart. Click on the Scatter chart and click the Insert button.
The chart will be placed on the spreadsheet and it can be position as needed. The data in the table is linked to the chart. As the data is changed the plots on the chart are updated accordingly.