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

If vec a and vec b are two unit vectors and theta be the angle between them,then sin((theta)/(2))=

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

If a and b are unit vectors and theta is the angle between them then a-b will be a unit vector if

If vec a and vec b are unit vectors and theta is the angle between them,then prove that cos[(theta)/(2)]=(1)/(2)|vec a+vec b|

If hata and hatb are two unit vectors and theta is the angle between them then vector 2hatb+hata is a unit vector if (A) theta= pi/3 (B) theta=pi/6 (C) theta=pi/2 (D) theta=pi