Show that if `veca+vecb,vecb+vecc,vecc+veca` are coplanar then `veca,vecb,vecc` are also coplanar.

If veca,vecb,vecc are coplanar,prove that veca+vecb,vecb+vecc,vecc+veca are coplanar.

If veca,vecb,vecc are three coplanar vectors, then [vecavecbvecc] is

Show that (veca-vecb) xx(veca+vecb)=2(veca xx vecb)

veca,vecb,vecc are three non zero vectors such that vecaxxvecb=vecc,vecbxxvecc=veca .Prove that veca,vecb,vecc are mutually at right angle and |vecb|=1,|vecc|=|veca| .

Prove that [ veca+vecb vecb+vecc vecc+veca]=2[veca vecb vecc]

If veca, vecb, vecc are unit vectors then, veca.veca =_____

Hence, show that veca.vecb+vecb.vecc+vecc.veca=(-3)/2 if veca+vecb+vecc=0 .

Show that the four points A, B, C and D with position vectors veca, vecb, vecc and vecd respectively are coplanar if 3 veca-2 vecb+vecc-2 vecd=0