多项式p(x)满足以下条件：
p(1) = p(3) = p(5) = 1
p(2) = p(4) = -1 该多项式的最小次数为
(A) 1
(B) 2
(C) 3
(D) 4答案： (D)
解释：
p(1) = p(3) = p(5) = 1
p(2) = p(4) = -1
The polynomial touches 0 at least once from 1 to 2, so there
is a root between 1 to 2
The polynomial touches 0 at least once from 2 to 3, so there
is a root between 2 to 3
Similarly, there is at least one root from 3 to 4 and 4 to 5.
So minimum degree is 4.这个问题的测验