Question

plzzz guyse prove it i had posted it in my twin sis brainly id but some of the nonsense people spam it plzzz ans it​

Answer 1

do as follows

cosX=(I+2j+3k).(2i-j)/√(14×5)

cosx=0

X=π/2

in general

X=(2n+1)π/2

Answer 2

Answer:

I hope it helps

Explanation:

please mark as brainlist