Mathematics

A polynomial in x whose zeros are -2, -1 and 3 is

A polynomial in x whose zeros are -2, -1 and 3 is
  • A.
    x3 – 7x + 6
  • B.
    x3 + 7x – 6
  • C.
    x3 + 7x + 6
  • D.
    x3 – 7x – 6
Correct Answer: Option D
Explanation

x = -2, x = -1 and x = 3
∴x+2 = 0, x+1 = 0 and x-3 = 0
Product of the factors
(x+2)(x+1)(x-3) = 0
(x2 + 3x + 2)(x-3)
x(x2 + 3x + 2) -3(x2 + 3x + 2) = 0
x3 + 3x2 + 2x – 3x2 – 9x – 6 = 0
x3 – 7x – 6 = 0