9514 1404 393
Answer:
(3, 0), (5, 0)
Explanation:
The vertex form of the equation for a parabola is ...
y = a(x -h)^2 +k
where the vertex is (h, k) and the vertical scale factor is 'a'. The y-intercept is ...
ah^2 +k = y-intercept
a = ((y-intercept) -k)/h^2 = (15 -(-1))/4^2 = 1
So, the equation is ...
y = (x -4)^2 -1 . . . . . vertex form with all the parameters filled in
The is zero when ...
0 = (x -4)^2 -1
(x -4)^2 = 1 . . . . add 1
x -4 = ±√1 . . . . . square root
x = 4 ± 1 . . . . . x-intercepts
The x-intercepts of the parabola are (3, 0) and (5, 0).