If `veca,vecb,vecc` are three vectors such that `|veca|=5,|vecb|=12 and |vecc|=13` and`veca+vecb+vecc=vec0`,find the value of `veca.vecb+vecb.vecc+vecc.veca`.

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

If veca, vecb, vecc are unit vectors such that veca+vecb+vecc=0 , find the value of veca.vecb+vecb.vecc+vecc.veca .

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

Find |veca-vecb| , if two vectors veca and vecb are such that |veca|=2,|vecb|=3 and veca. vecb=4

If veca, vecb , vecc are the three vectors mutually perpendicular to each other and |veca| =1 , |vecb| = 3 and |vecc| = 5, then [veca -2 vecb, vecb - 3 vecc , vecc - 4 veca] is equal to a)0 b)-24 c)3600 d)-215

For any three vectors veca,vecb and vecc , and, prove that (veca+vecb)+vecc=veca+(vecb+vecc) .

If veca=vecb+vecc, then is it true that |veca|=|vecb|+|vecc| ? Justify your answer.