If two vectors P→=i^+2mj^+mk^ and Q→=4i^–2j^+mk^ are perpendicular to each other. Then, the value of m will be [2023]
(2)
P→·Q→=0
(i^+2mj^+mk^)·(4i^–2j^+mk^)=0 ⇒ 4–4m+m2=0
⇒ (m–2)2=0 ⇒ m=2