Question

What are the vertex and x-intercepts of the graph of the function given below?

y=x²-2x-48
O A. Vertex: (-1, -21); intercepts: x = 6,4
B. Vertex: (1, -40); intercepts: x = 6,7
C. Vertex: (1,-49); intercepts: x = 8,-6
D. Vertex: (0, 0); intercepts: x= -4, 6
SUBMIT

Answer 1

C. Vertex: (1,-49); intercepts: x = 8,-6

Explanation:

x²-2x-48 = (x²-2x +1) - 1 - 48

= (x - 1)² - 49

Then

The vertex is (1 , - 49)

==================

x²-2x-48 = 0

⇔ (x - 1)² - 49 = 0

⇔ (x - 1)² = 49

⇔ x - 1 = 7 or x - 1 = -7

⇔ x = 8 or x = -6

Then

intercepts: x = 8,-6