WAEC Further Mathematics 2012 Question 8

Question 8

Vectors

From the diagram, which of the following represents the vector V in component form?

Diagram for this question
  1. A.−5√3i + 5j
  2. B.3i + 3√3j
  3. C.i + 2√3j
  4. D.−2√3i − j
Show the answer and explanation

Answer: B (3i + 3√3j)

Explanation

V has magnitude 6 at 60° to the i-axis: 6cos60° i + 6sin60° j = 3i + 3√3j.