if vector A=i cap *A cos thita + j cap *A sin thita, then another vector B , WHICH IS PERPENDICULAR TO VECTOR A,can be expressed as?give detailed answer?

Answer 1

A = |A| cos thita i + |A| sin thita j
B = x i + y j
A dot B = 0 for perpendicular

|A| x cos thita + |A| y sin thita = 0

if x = -sin thita and y = cos thita
that works
(also the opposite of course)