Question

v) Given v, = 5i+2j and v2 = ai-6j are
perpendicular to each other, determine the
value of a.
Ans:12upon 5​

Answer 1

V1.V2 = |V1|*V2 cos90

(5i+2j )(ai-6j )=0

5a - 12=0

a = 12/5

Answer 2

Answer:

$a=\frac{12}{5}$

Explanation:

Given v, = 5i+2j and v2 = ai-6j are  perpendicular to each other.

Since it is given that two vectors are perpendicular to each otherThat means angle between them is 90 degre.

we know the definition of dot or scalar product which is

$a.b=|a||b|cos$α.........................(1)

here $\alpha =90$

let a=5i+2j ,b=ai-6j

using (1) we get

(5i+2j).(ai-6j)=0 as cos90=0

5a-12=0

5a=12

$a=\frac{12}{5}$