LET’S TRY ONE
For y = (x + 4)2 + 3, what is the x-coordinate of the vertex?
-4
The squared term is zero when x = -4. The vertex is (-4, 3), so its x-coordinate is -4.
Learning steps & teaching tips
Find the vertex’s x-coordinate from a completed-square expression.
- Find the x-value that makes the squared expression zero.
- Work through the example and explain why each operation is used.
- Estimate or use another method to check the result before choosing.
Try it together
Work with a partner: solve one example, explain the method, then change one number and predict what changes.
Find the x-value that makes the squared expression zero.