Question

If P = aî+ bĵ and Q = cî + dĵ are perpendicular to each other then:
A) ac = bd
B) ab = cd
C) a/b = -d/c
D) a/c = b/d​

Answer 1

Explanation:

if P and Q vector are perpendicular

then their dot product or

P. Q= |P| |Q| cos theta

theta between them is 90 °

cos 90°=0

P. Q =0

or, ac +bd =0

or ac =-bd

a/b= -d/c

option (C)