passwella.
Menu

WAEC Further Mathematics 2022 Question 9

Question 9

Differentiation

If x2 + y2 − 2x − 6y + 5 = 0, evaluate dy/dx when x = 3 and y = 2.

  1. A.−2
  2. B.2
  3. C.4
  4. D.−4
Show the answer and explanation

Answer: B (2)

Explanation

2x + 2y dy/dx − 2 − 6 dy/dx = 0, so dy/dx = (2 − 2x)/(2y − 6) = (2 − 6)/(4 − 6) = 2.