For this to occur, the minimum point must be above the y axis
The minimum point occurs at x=1/2 and subbing that in, we have y=-3/4 + 3p-2 = 3p-11/4
But this has to be greater than 0, so 3p-11/4 > 0. Solving his, we have p > 11/12.
Alternatively, you could let the discriminant be less than than zero, since we already know that it's a positive quadratic.