Answer:
see explanation
Explanation:
the equation of a quadratic in vertex form is
y = a(x - h)² + k
where (h, k ) are the coordinates of the vertex and a is a multiplier
y = x² - 4x - 1
using the method of completing the square
add/subtract ( half the coefficient of the x- term)² to x² - 4x
y = x² + 2(-2)x + 4 - 4 - 1
y = (x - 2)² - 5
with vertex = (2, - 5 )