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.
Input(x) | Output(y) |
---|---|
0 | 0 |
2 | 4 |
4 | 8 |
6 | 12 |
8 | 16 |
Step 1:
From the table, we get the coordinates of the points as (0, 0), (2, 4), (4, 8), (6, 12), and (8, 16)
Step 2:
Making a plot of these points, we get
The graph of a function is given below. Fill in the table for this function.
Step 1:
From the graph plot, we get the coordinates of the points as (0, 0), (1, 4), (2, 9), (3, 5), and (4, 10)
Step 2:
Making a table of the x and y values, we get
Input(x) | Output(y) |
---|---|
0 | 0 |
1 | 4 |
2 | 9 |
3 | 5 |
4 | 10 |