Q&A for How to Draw a Graph

The value of a dependent variable depends on the value of some other variable. The value of an independent variable can be anything you choose and doesn't depend on the value of any other variable. For example, in the expression x = 3y, the value of y can be any number you choose and is therefore called an independent variable. However, the value of x would always be three times the value of y and is therefore dependent on y's value, which makes x a dependent variable.

A graph is a quick way of displaying data.

A pictorial representation of two physical variables recorded by an experiment.

If you only have points, find the slope. The basic equation of a line is Y = MX + B. Y is a y-value, and X is the corresponding x-value of the same coordinate. M is slope, and B is the y-value when x = 0.

You could call them the horizontal axis and vertical axis, respectively.

A portion of the coordinate plane will be "shaded," showing the area in which the inequality is true.

First draw two lines: one going straight vertically and one going straight horizontally (y and x lines, respectively). They should make a plus sign shape. Then, grab a ruler and measure ticks every 1 cm from the centre where the two lines cross, going left, right, up, and down. Now, you label your lines and graph!

Assign convenient values to the independent variable. Then calculate the corresponding values of the dependent variable.

It's in both axes. It's called the "origin," and it's the point of intersection of the y-axis and x-axis.

Just set up two columns, one for the independent variable, the other for the dependent variable. Choose convenient values for the independent variable, and calculate the accompanying values for the dependent variable. (For example, in the equation y = 2x + 1, x is the independent variable, and y is the dependent variable. Choose relatively small values for x (for ease of calculation), such as 2, 1, 0, -1, and -2. Then calculate the corresponding y values. They would be, respectively, 5, 3, 1, -1 and -3.) At this point you can plot the graph.

You could make two separate graphs, one for production, the other for sales. In each graph you would plot either the production data or the sales data against a time period. For instance, in the production graph you would show units produced on one axis and the years of production on the other axis. You could then compare the two graphs, showing, for instance, how production affected sales over time.

If the equation of the graph takes the form of y = mx + b, m is the slope. Otherwise, you would have to measure the slope manually by counting the number of vertical units there are between two points on the graph line, and divide that by the number of horizontal units there are between those same two points. (In other words, the slope between two points is the change in y divided by the change in x.)

If you want a line graph, label one of the axes "month" and the other axis "rainfall." If you want a bar graph, let each bar represent a given month, and the height of each bar represents the amount of rain in that month.

Draw a straight horizontal line, and label it "x." Near the middle of that line intersect it with a straight vertical line labeled "y."