CPM Homework Help : CAAC Problem 8-68

The roots (x-intercepts) of y = 2x² − 16x + 30 are (3, 0) and (5, 0). Homework Help ✎
1. What is the x-coordinate of the vertex? How do you know?
2. Use your answer to part (a) above to find the y-coordinate of the vertex. Then write the vertex as a point (x, y).

Hint (a):

The x coordinate of the vertex is halfway between 3 and 5.

Answer (a):

x = 4

Hint (b):

Substitute the vertex value of x back into the original equation to find y.

Hint (b):

y = 2(4²) − 16(4) + 30

Solve for y.

Answer (b):

y = −2

Coordinates = (4, −2)