Question

69. If a vector (2î +31 + 8k) is perpendicular to the
vector (49 - 4i + ak), then the value of a is:
(1)-1
(2) 1/2
(3)-1/2
(4) 1

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Answer 1

Answer:

C.3.....................................

Answer 2

Answer:

(4)

Explanation:

because the dot product is zero so multipply coefficients of i into i and coefficients of k into k and put the result equal to zero then you get the answer which is 1