If O be the origin and `A(x_(1), y_(1)), B(x_(2), y_(2))` are two points, then what is `(OA) (OB) cos angle AOB` ?

If O is the origin and if A(x_(1), y_(1)), B(x_(2), y_(2)) are two points then OA*OB*cos angleAOB=

If O is the origin and A(x_(1),y_(1)),B(x_(2), y_(2)) are two points then OA*OB*sin angleAOB=

If O is the origin and P(x_(1),y_(1)), Q(x_(2),y_(2)) are two points then POxxOQ sin angle POQ=

If O is the origin and P(x_(1),y_(1)), Q(x_(2),y_(2)) are two points then OPxOQ sin angle POQ=

If O be the origin and if P(x_1, y_1) and P_2 (x_2, y_2) are two points, the OP_1 (OP_2) sin angle P_1OP_2 , is equal to

If O be the origin and if P(x_(1),y_(1)) and P_(2)(x_(2),y_(2)) are two points,the OP_(1)(OP_(2))COS/_P_(1)OP_(2), is equal to

If O is origin,A(x_(1),y_(1)) and B(x_(2),y_(2)) then the circumradius of Delta AOB is