Let r be a vector perpendicular to a + b + c , where [ a b c ] = 2. If r = l( b c ) + m( c a ) + n( a b )...

Question

Let r be a vector perpendicular to a + b + c , where [ a b c ] = 2. If r = l( b c ) + m( c a ) + n( a b ) then l + m + n is

Accepted Answer

(C)

JEE Advanced Mathematics question