F(x)=x^2−x−1
over which interval does f have an average rate of change of zero?
choose 1
(choice a)
2≤x≤3
(choice b)
−5≤x≤5
(choice c)
2−1≤x≤2
(choice d)
−3≤x≤−2

C. -1 < x < 2.

Step-by-step explanation:

Change to vertex form to find the axis of symmetry:

x^2 − x −1

= (x - 0.5)^2 - 0.25 - 1

= (x - 0.5)^2 - 1.25.

Thus the graph is symmetrical about x = 0.5.

So the interval must be equal lengths either side of x = 0.5.

That would be  -1 < x < 2.

the solution is 12x-6y