Question 405529
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Hi
Using the vertex form of a parabola, {{{y=a(x-h)^2 +k}}} 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, &#8734;)
{{{drawing(300,300, -6, 6, -6, 6, grid(1),
circle(5,-4,0.3),
graph( 300, 300, -6, 6, -6, 6,x^2-10x+21 ))}}}