devarshi-dt-logo

Question:

If a vector 2^i + 3^j + 8^k is perpendicular to the vector 4^i + 8^j + α^k, then the value of α is:

12

2

1

Solution:

For perpendicular vectors, →A ⋅ →B = 0
(2^i + 3^j + 8^k) ⋅ (4^i + 8^j + α^k) = 0
8 - 24 + 8α = 0
-16 + 8α = 0
8α = 16
α = 2