Find the value of the constant k for which (a = 4 i – k j) and (b = 3 i + 8 j) are perpendicular.
-
A.
(frac{2}{3}) -
B.
2 -
C.
3 -
D.
(frac{3}{2})
Correct Answer: Option D
Explanation
For perpendicular vectors, their dot product = 0.
((4i – kj). (3i + 8j) = 12 – 8k = 0)
(8k = 12 implies k = frac{3}{2})