Question: #8) Indicate if the graph will have a maximum or a minimum:

(a) \(f\left( x \right)={{x}^{2}}-9\)

(b) \(f\left( x \right)=8x-3{{x}^{2}}\)

(c) \(f\left( x \right)=-{{\left( 3-x \right)}^{2}}\)