If A= ⎡⎢⎣a1a2a3b1b2b3c1c2c3⎤⎥⎦ and rank (A) < 3, then ¯¯¯a=(a1,a2,a3);¯¯b=(b1,b2,b3) ;¯¯c=(c1,c2,c3) are