Question

PLEASEEE HELPP !!!

What are the coordinates of the vertex of the parabola y = x² - 2x - 1?
a. (-1,2)
b. (1,2)
c. (-1,-2)
d. (1,-2)

Answer 1

D) (1,-2)

Explanation:

The vertex is the maximum or minimum (highest or lowest) point of a parabola. x-value of vertex of a parabola for standard form is: -b/2a.

Plug in given:

a = 1

b = -2

c = -1

-(-2) / 2(1)

2/2

1

x-value of vertex: 1

Plug in 1 back into the equation to find the y-value of the parabola.

y = (1)^2 - 2(1) - 1

y = 1 - 2 - 1

y = -2

Answer 2

• D) (1, - 2)

------------------------

Given

• Parabola y = x² - 2x - 1

To find its vertex convert this to vertex form by completing the square

Vertex form

• y = a(x - h)² + k, where (h, k) is the vertex

Convert

• y = x² - 2x - 1
• y = x² - 2x + 1 - 2
• y = (x - 1)² - 2

• The vertex is (1, - 2)

Correct choice is D