Consider the quadratic function: f(x) = x2 – 8x – 9

Vertex: (StartFraction negative b Over 2 a EndFraction, f (StartFraction negative b Over 2 a))

x=-b/2a=8/2=4

y=16-8*4-9=16-32-9= - 25

(4, - 25) ,,

question: how many people can she serve?

answer: she can serve 16.66666667 people. so she can only give 16 people a complete serving.

question: does she have enough ice cream for her guests?

answer: no. explanation: she only has enough for 16 people to have a full serving. however, she can give a 17th person a partial serving.