y = - 2x^2 + 2x
y = Ax^2 + Bx + C ; if A > 0, the graph is open up and there is min
if A < o, the graph is open down and there is max
A = - 2 ⇒ there is max
x(max) = - B/2A ( formula )
x(max) = - 2/(-2*2) = 1/2 = 0.5
x = 1/2 ⇒ y = -2(1/2)^2 + 2* 1/2 = 1/2
max (0.5: 0.5 )