If →a,→b&→c are 3 non-coplanar vectors and →p,→q&→r are vectors defined by →p→b×→a[→a→b→c],→q=→c×→a[→a→b→c] and →r=→a×→b[→a→b→c], and, then the value of (→a+→b).→p+(→b+→c).→q+(→c+→a).→r=
3
(¯a+¯b).¯bׯc[¯a¯b¯c]+(¯b+¯c).¯cׯa[¯a¯b¯c]+(¯c+¯a).¯aׯb[¯a¯b¯c]=¯a.(¯bׯc)+0+¯b.(¯cׯa)+0+¯c.(¯aׯb)+0[¯a¯b¯c]=3