Tables
Tables
Example 3
Find the equation that models this table in vertex form.
x | -2 | -1 | 0 | 1 | 2 | 3 | 4 |
y | 12 | 9 | 7 | 6 | 6 | 7 | 9 |
Step 1 . Find the second difference.
x | -2 | -1 | 0 | 1 | 2 | 3 | 4 |
y | 12 | 9 | 7 | 6 | 6 | 7 | 9 |
Step 2. Find the a-value.
The a-value is found by dividing the second difference by 2.
Step 3. Find the h-value.
The h-value is the x-coordinate of the vertex. Due to symmetry, the x-coordinate of the vertex is 1.5. Therefore, h = 1.5.
Step 4. Find the k-value.
Substitute a and h into the equation and solve for k.
Step 5 . Substitute a, h and k into the equation.
