$\Delta= P !( P +1) !( P +2) !\left|\begin{array}{ccc}1 & 1 & 1 \\P +1 & P +2 & P +3 \$ P +2)( P +1) & ( P +3)( P +2) & ( P +4)( P +3)\end{array}\right|$
$\Delta=2 P !( P +1) !( P +2) !$
Which is divisible by $P ^{\alpha}\,and\,( P +2)^{\beta}$
$\therefore \alpha=3, \beta=1$