f(x)=6x²-6x+128
1) This parabola has a maximum (open down) since the coefficient of x² (that is 6) is positive.
2) It doesn't intercepts the x-axis since its roots are imaginary :
x' =4.292 i & x" = -4.592 i
3) its axis of symmetry = -b/2a = 1/2 ===> x= 1/2
The tan at the minimum ===> dy/dx = 12x-6 ===>(x=1/2), dy/dx =0
This parabola is decreasing in the interval ]x=-∞, 0[ ∪ ]0, ∞[
minimum (1/2, 126.5)
