Answer:
[-1,infinity)
Step-by-step explanation:
We want to find the minima or maxima of the quadratic (vertex)
Convert to vertex form: y=x^2-4x-1
y=x^2-4x+4-5
y=(x-2)^2-1
Vertex is at (2,-1)
The graph opens up as the first term is positive
[-1,infinity) is the range