Question

If the graph of a function 𝑓(𝑥) = 𝑎(𝑥 − h)2 + 𝑘, where 𝑎, h, 𝑘 > 0, passes through the points (𝑟, 𝑡) and (𝑠, 𝑡), find 𝑓 ((𝑟+𝑠)/2)

Answer 1

The vertex is at (h,k) and it lies on the line x=(r+s)/2
so f((r+s)/2) = k