passwella.
Menu

WAEC Further Mathematics 2026 Question 40

Question 40

Integration

Given that dy/dx = 3x2 − 5, and y = 12 when x = 4, find y

  1. A.y = x3 + 5x − 32
  2. B.y = x3 − 5x + 32
  3. C.y = x3 − 5x − 32
  4. D.y = x3 + 5x + 32
Show the answer and explanation

Answer: C (y = x3 − 5x − 32)

Explanation

Integrating: y = x³ − 5x + k. With x = 4, y = 12: 12 = 64 − 20 + k, so k = −32 and y = x³ − 5x − 32.