A → opens down, B → maximum, C → x = 0, (0, 5) and 5
For a parabola of the form y = ax² + c
• If a > 0 then opens up and is a minimum
• I f a < 0 then opens down and is a maximum
the y- intercept = c and the vertex = (0, c)
The axis of symmetry is the y- axis, that is x = 0
f(x) = -5x² + 5 is in this form with a = - 5 < 0 and c = 5
Thus the parabola opens down and is a maximum
The axis of symmetry is x = 0, vertex = (0, 5) and y-intercept = 5
