Question

Any vector à is given by A = xi + yj. The another vector 3 perpendicular to Ā can be written as
(A) xi-yj
B) yi-
xi
(C) –xi + yj
(D) –yi - xj​

Answer 1

Given,

A = xî+ yj

Now, there are two possible vectors which can be perpendicular to A

(Refer to the figure)

So, the option(s) can be:-

(A) xi-yj

(B) -xi+yj

(C) -xi+yj

Cheers!

Answer 2

Answer:

Explanation:

when a vector a is perpendicular to vector b , it means A.B=0

now try the hit and trial method-

option-a-

(xi-yj).(xi -yj)=0

answer will come as x^2-y^2

answer is inccorrect , not equals to zero

option b-

(xi-yj).(yi-xi)=0

answer wil come as xy-yx

which is equal to zero so the option is correct.

option c-

(xi-yi)(-xi+yj)=0

answer will come as  -x^2-y^2

so the option is incorrect

option d-

(xi+yj)(-yi-xj)=0

answer will come as -xy-yx not equals to zero.

so the correct option is b