Question

7. Prove that vectors Ā=i +2j+3K and B = 2i-j - are perpendicular to each other.​

Answer 1

Answer:

Solution

We have

a=i+2j−3k

b=3i−j+2k

∴a+b=4i+j−k

a−b=−2i+3j−5k

Then

(a+b).(a−b)=−8+3+5=0

Hence,

∴(a+b)⊥(a−b)

Proved.