If `hata` and `hatb` are unit vectors, then prove that `|hata + hatb| = 2 cos (theta/2)`, where `theta` is the angle between them.

If hat a and hat b are unit vectors such that [ hata hatb hatatimeshatb ]= (1)/(4) ,then the angle between hat a and hat b ,is equal to

If hata and hatb are unit vectors and theta is the angle between them show that sin (theta/2)= 1/2 |hata-hatb|

If hata and hatb are unit vectors inclined at an angle theta then prove that cos "" theta /2 = 1/2 |hata + hatb|

If hata and hatb are unit vectors inclined at an angle theta then prove that tan "" theta /2 = | (hata -hatb)/(hata+hatb)|

If hata and hatb are unit vectors then the vector defined as vecV=(hata xx hatb) xx (hata+hatb) is collinear to the vector :

If theta is the angle between the unit vectors hat a and hat b then cos (theta/2) is equal to