WAEC Further Mathematics 2015 Question 5

Question 5

Binomial Theorem

Find the third term of (x/2 − 1)8 in descending order of x.

  1. A.x7/8
  2. B.7x6/16
  3. C.7x5/4
  4. D.(35/8)x4
Show the answer and explanation

Answer: B (7x6/16)

Explanation

Third term = ⁸C₂(x/2)⁶(−1)² = 28x⁶/64 = 7x⁶/16.