SOLUTION: what is the range of the function y=x^2-10x+21 ??

Hi

Using the vertex form of a parabola,  where(h,k) is the vertex

y=x^2-10x+21  |completing square to put into vertex form

y = (x-5)^2 -25 + 21

y = (x-5)^2 - 4 |Vertex is Pt(5,-4) Parabola opens upward (a>0)

Range is [-4, ∞)