Question

Find the x-intercept(s) and the coordinates of the vertex for the parabola =y−x2−4x5. If there is more than one x-intercept, separate them with commas.

x-Intercept(s):
Vertex:

Answer 1

x-intercepts -1, 5.

Vertex is at (2, -9).

Explanation:

y = x^2 - 4x - 5

Completing the square:

y = (x - 2)^2 - 2^2 - 5

y = (x - 2)^2 - 9 which is vertex form.

So the coordinate of the vertex are (2, -9).

Finding the x-intercepts:

(x - 2)^2 - 9 = 0

(x - 2)^2 = 9

x - 2 = +/- 3

x = 3 + 2 or -3+2

= 5, -1.