A polynomial p(x) satisfies the following:
p(1) = p(3) = p(5) = 1 p(2) = p(4) = -1
The minimum degree of such a polynomial is
(A) 1
(B) 2
(C) 3
(D) 4
Answer: (D)
Explanation:
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.