When the roots of the polynomial
P(x)=(x−1)1(x−2)2(x−3)3(x−4)4(x−5)5(x−6)6(x−7)7
are removed from the number line, what remains is the union of 8 disjoint open intervals. On how many of these intervals is P(x) positive?
3
7
6
4
5
