Question

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Answer 1

Step-by-step explanation:

Note: Two vectors are perpendicular if their dot product is 0.

Given vectors are :

a = 3i + 5j - 7k.

b = 7i + 3k

So,

a.b = (3i + 5j - 7k).(7i + 3k)

     = 3 * 7 - 7 * 3

     = 21 - 21

     = 0.

Therefore, the two vectors are perpendicular to each other.

Hope it helps!

Answer 2

a.b = (3i + 5j - 7k).(7i + 3k)

     = 3 * 7 - 7 * 3

     = 21 - 21

     = 0.