Question

Given v1=5i+2j and v2 =ai-6j are perpendicular to each other, determine the value of a.

Answer 1

Answer:

cos 90⁰ = v1.v2/

$\sqrt{v1. \sqrt{v2} }$

0 = 5a - 12

a = 12/5

a = 2 . 4

Hope this helps you

Answer 2

Answer:

12/5.

Explanation:

Since, the two vectors are perpendicular o each other hence there dot product will be zero so the dot product of the two vectors will be given as modulus of v1.v2 which will be 5a-12=0.

Thus, on solving we will get the value of a as 12/5. Since, there are only to vectors that are perpendicular hence we can find it by dot product and no λ is required.