Question

if a bar is perpendicular to b bar then​

Answer 1

Answer:

given

A bar is perpendicular to b bar

so, A bar.B bar = 0 but A bar × B bar ≠ 0

then,

A bar [ A bar + B bar]

= A bar.A bar + A bar.B bar

= A²+0 ( since A bar.B bar = 0)

= A²

A bar[A bar + B bar ] = A²

.

. . Option B is correct✔

Answer 2

Given , A bar is perpendicular to B

Therefore ,  A bar . B bar = 0       ( cos 90° = 0 )

                    A bar × B bar ≠ 0     ( sin 90° = 1 )

then,

A bar [ A bar + B bar]

= A bar.A bar + A bar.B bar

= A²+0 ( since A bar.B bar = 0)

= A²

⇒A bar[A bar + B bar ] = A²

Answer : B