Question Detail
Question
Given that A = i + 4j, B = 2i - 3j, C = i + k, find the triple product (A × B) · C.
Correct Answer
Option D is the correct answer.
Detailed Explanation
First compute A × B. A = (1,4,0), B = (2,-3,0). A × B = (4×0 - 0×(-3), 0×2 - 1×0, 1×(-3) - 4×2) = (0, 0, -3 - 8) = (0,0,-11). So A × B = -11k. Then (A × B) · C = (-11k) · (i + k) = (-11k)·i + (-11k)·k = 0 + (-11)(1) = -11. So the scalar triple product is -11. Option A is -11.
Hint
Compute the cross product first, then dot with C.