The maximum or minimum point can be obtained by obtaining an expression of the slope of the curve and equating this to zero. The slope of the curve can be obtained by dg/dx
therefore
dg/dx = 200x - 1100
equating this equation to zero
dg/dx = 0 = 200x - 1100
therefore x = 5.5
there g(x) = 100* (5.5)^2 - 1100*5.5 = -3025
hope this helps
