Find the minimum or maximum value of the function g(x)= -(x-2)^2-3

Neato

assuming you mean

remember
in form

a is leading coficient
(h,k) is vertex
k will be the minimum or max value of the function
if a is positive, then the parabola opens up and k is minimum
if a is negative, then the parabola opens down and k is max

given

a is negative
the parabola opens down and k is the max value
it is -3
the max value is -3, which occors at x=2
g(2)=-3 is max