Question

Which rule below represents a quadratic function with vertex (4 ,-5) and passing through the point
(0, -1)?


y=(x-4)(x+5)-1
y=(x-4)^2-5
y = 0.25 (x - 4)^2 - 5
y = 0.12 (x - 4)^2 - 5

Answer 1

Y = a(x-h)^2 + k = -1.
a(0-4)^2 - 5 = -1
16a - 5 = -1.
16a = 4.
a = 0.25.

Y = 0.25(x-4)^2 - 5.