4. Graphing a Function Rule
Sign In
One way to graph a function rule is by making a table of values and substituting some arbitrary values for x. Doing so will give the corresponding values of y, which we can use to form (x,y) coordinate pairs.
x | -x2+2 | y | (x,y) |
---|---|---|---|
-2 | -(-2)2+2 | -2 | (-2,-2) |
-1 | -(-1)2+2 | 1 | (-1,1) |
0 | -(0)2+2 | 2 | (0,2) |
1 | -(1)2+2 | 1 | (1,1) |
2 | -(2)2+2 | -2 | (2,-2) |
Let's plot these points on a coordinate plane.
By connecting all of our points, we form the graph of the function rule. Because there is a variable with an exponent in the function, our line will not be straight. Later, we will learn that this type of function is called a quadratic function, and this type of graph is called a parabola.