passwella.
Menu

WAEC Further Mathematics 2012 Question 3

Question 3

Polynomials

Solve the inequality x2 − 2x ≥ 3

  1. A.−1 ≤ x ≤ 3
  2. B.x ≥ 3 or ≤ −1
  3. C.x > 3 x ≤ −1
  4. D.−1 ≤ x < 3
Show the answer and explanation

Answer: B (x ≥ 3 or ≤ −1)

Explanation

x2 − 2x − 3 = (x − 3)(x + 1) ≥ 0. Both factors have the same sign (or one is zero) when x ≥ 3 or x ≤ −1.