A function is a rule that takes in and works on an input and gives an output. It is usually represented as f(x) = y, where x is the input variable and y is the output variable.
By giving different whole number values to x, values of y can be found from the function rule. The x and y values are put in a table and then plotted as a graph.
Plotting a graph
So, from a function rule, x and y values can found and put in a table and also plotted as a graph.
Conversely, from a graph we can find x and y values and make a table of those values and find the function rule for the given graph also.
The table below describes a function. Graph this function.
From the table, we get the coordinates of the points as (0, 0), (2, 4), (4, 8), (6, 12), and (8, 16)
Making a plot of these points, we get
The graph of a function is given below. Fill in the table for this function.
From the graph plot, we get the coordinates of the points as (0, 0), (1, 4), (2, 9), (3, 5), and (4, 10)
Making a table of the x and y values, we get