find min or max value

Question

f(x)=3-x-1/2x^2

 

 

g(x)=2x(x-3)+7

Answer 1

These are quadratic functions; the graphs are parabolas; the min or max is at the vertex; for vertex, x = -b/(2a), using a and b from Standard for of the equation (y =ax²+bx+c).