What is the vertex form of y=x^2+9x+28 ?

1 Answer
May 9, 2018

Vertex form of equation is y = (x +4.5)^2 + 7.75

Explanation:

y = x^2 + 9 x +28 or

y = (x^2+ 9 x +4.5^2) - 4.5^2+ 28 or

y = (x +4.5)^2 - 20.25+ 28 or

y = (x +4.5)^2 + 7.75 Comparing with vertex form of

equation f(x) = a(x-h)^2+k ; (h,k) being vertex we find

here h= -4.5 , k=7.75 :. Vertex is at ( -4.5,7.75)

and vertex form of equation is y = (x +4.5)^2 + 7.75

graph{x^2+9 x+28 [-35.56, 35.56, -17.78, 17.78]} [Ans]