Linear Function? Yes. Description: The value of y is equal to - 11 times x plus 43. Equation: y=- 11x+43 Graph:
Practice makes perfect
The graph of a linear function is a straight, non-vertical line. To determine whether the relation in the table is a linear function, let's first confirm that the relation is a function.
Words
Since each input x has only one output, the relation in the table is a function. Let's look for a pattern of change in the given table.
Change in x
x
y
Change in y
0
43
+1
1
32
-11
+1
2
21
-11
+1
3
10
-11
We can see that every time the x-values increase by 1, the y-values decrease by 11. This might lead us to believe that the relationship is just - 11 times x. However, by testing the values of x with this relationship, we can see that the resulting values of y are not equal to the given values.
- 11* x&? =y
- 11* 0&≠43
- 11* 1&≠32
Assuming y is equals to -11 times x, the values of y are 43 less than we need in each case. Therefore, we can say that the value of y is equal to -11 times x plus 43.
Equation
To describe the relation with an equation, let's translate our verbal description into algebraic terms.
the value ofy is equal to
- 11timesxplus43
y = - 11x+43
Graph
Now, let's graph the points. By doing so, we will also be able to determine if the relationship is a linear function.
The graph of a linear function is a straight, non-vertical line. Now that we have graphed the given points, we can see that they are able to be connected with a straight line. The relationship is therefore linear.
