Question

Create a graph; then answer the following question.

What are the key points on the graph of y=x2−8x
? Name the vertex, x-intercept(s), and y-intercept.

(1 point)

x-intercepts: (0,0)
(8,0)


y-intercept: (0,0)


vertex: (4,−16)



x-intercepts: (0,0)
(0,8)


vertex: (4,−16)


There is no y-intercept.


x-intercept: (4,−16)


y-intercept: (0,0)


vertex: (8,0)



x-intercept: (0,8)


y-intercept: (0,0)

Answer 1

y = x^2 − 8x = x(x − 8)

x-intercepts: set y=0 → x=0 and x=8 → (0,0), (8,0)
y-intercept: x=0 → y=0 → (0,0)
vertex: complete the square: y = (x−4)^2 − 16 → vertex at (4, −16)

(Parabola opens upward, axis of symmetry x=4.)